Patent Application
20060200191
1. Field of the Invention
Certain embodiments disclosed relate to treating an intravascular occlusion. The methods are particularly well suited for treating stenoses or occlusions within saphenous vein grafts, coronary arteries, cerebral arteries and similar vessels.
2. Description of the Related Art
Human blood vessels often become occluded or completely blocked by plaque, thrombi, emboli or other substances, which reduces the blood carrying capacity of the vessel. Should the blockage occur at a critical location in the circulation, serious and permanent injury, or death, can occur. To prevent this, some form of medical intervention is usually performed when significant occlusion is detected, such as during an acute myocardial infarction (AMD.
Coronary heart disease is the leading cause of death in the United States and a common occurrence worldwide. Damage to or malfunction of the heart is caused by narrowing or blockage of the coronary arteries (atherosclerosis) that supply blood to the heart. The coronary arteries are first narrowed and may eventually be completely blocked by plaque, and may further be complicated by the formation of thrombi (blood clots) on the roughened surfaces of the plaques. AMI can result from atherosclerosis, especially from an occlusive or near occlusive thrombus overlying or adjacent to the atherosclerotic plaque, leading to death of portions of the heart muscle. Thrombi and emboli also often result from myocardial infarction, and these clots can block the coronary arteries, or can migrate further downstream, causing additional complications.
The carotid arteries are the main vessels which supply blood to the brain and face. The common carotid artery leads upwards from the aortic arch, branching into the internal carotid artery which feeds the brain, and the external carotid artery which feeds the head and face. The carotid arteries are first narrowed and may eventually be almost completely blocked by plaque, and may further be complicated by the formation of thrombi (blood clots) on the roughened surfaces of the plaques. Narrowing or blockage of the carotid arteries is often untreatable and can result in devastating physical and cognitive debilitation, and even death.
Various types of intervention techniques have been developed which facilitate the reduction or removal of the blockage in the blood vessel, allowing increased blood flow through the vessel. One technique for treating stenosis or occlusion of a blood vessel is balloon angioplasty. A balloon catheter is inserted into the narrowed or blocked area, and the balloon is inflated to expand the constricted area. In many cases, near normal blood flow is restored. It can be difficult, however, to treat plaque deposits and thrombi in the coronary arteries, because the coronary arteries are small, which makes accessing them with commonly used catheters difficult. Other types of intervention include atherectomy, deployment of stents, introduction of specific medication by infusion, and bypass surgery.
Furthermore, the fear of dislodging an embolus from an ulcerative plaque and the severe resulting consequences has prevented the widespread use of angioplasty in the carotid arteries. Because of the potential complications, the options for minimally invasive treatment of the carotid arteries are severely limited.
Carotid endarterectomy is another type of intervention for removal of blockages from the carotid arteries. In endarterectomy, the carotid bifurcation is exposed through an incision in the neck of the patient. Clamps are placed on either side of the occlusion to isolate it, and an incision made to open the artery. The occlusion is removed, the isolated area irrigated and aspirated, and the artery sutured closed. The clamps are removed to reestablish blood flow through the artery. In carotid endarterectomy, the emboli and debris are contained and directed by activating and deactivating the clamps. For example, after the clamps are in place, one on the common carotid artery and one on the internal carotid artery, the particles are contained between the two clamps. After the occlusion is removed, the clamp on the common carotid artery is opened, allowing blood to flow into the previously isolated area toward the clamp on the internal carotid. This blood flow is then aspirated through an external aspiration tube. The common carotid artery is then reclamped, and the clamp on the internal carotid opened. This causes blood to flow into the previously isolated area toward the clamp on the common carotid artery. The flow is then aspirated. The clamp on the internal carotid artery is closed, and the artery is sutured closed. This method allows for the flushing of debris into the area where aspiration occurs.
Alternatively, this method of clamping and unclamping the carotid arteries can be done after the incision in the artery is sutured closed. Using this method, it is hoped that any particles in the internal carotid artery will be forced back to the common carotid artery, then into the external carotid area, where serious complications are unlikely to arise from emboli.
Carotid endarterectomy is not without the serious risk of embolization and stroke caused by particles of the blocking material and other debris moving downstream to the brain, however.
There is therefore a need for improved methods of treatment of occluded vessels which decrease the risks to the patient.
In one embodiment of the present invention, a method is provided for treating an intravascular occlusion. The method comprises delivering fluid containing an occlusion-treating drug at a location proximal to an intravascular occlusive device. The occlusive device may be a balloon, while the drug may be a thrombolytic agent, an anticoagulant or a radioisotope. The occlusive device is preferably delivered on a guidewire, with the occlusive device being actuated once the device is delivered distal to the occlusion. The drug is preferably delivered at a rate of between about 0.1 and 10 cc/second. In one embodiment, the drug travels proximally to distally, and once the drug or at least a portion thereof contacts the device, the drug or portion thereof travels in a distal to proximal direction, i.e., against the flow of blood. Correspondingly, because blood is flowing proximally to distally in the vessel, the blood flow localizes the drug at a desired treatment site in order to treat the occlusion.
The fluid-containing drug is preferably delivered through a catheter riding over the guidewire. In one embodiment, the catheter is an aspiration catheter. This allows the same lumen used for delivering drugs to aspirate any particles broken off by the drug treatment. Because the occlusive device is preferably actuated continuously during both drug delivery and aspiration, by delivering drugs and aspirating through the same catheter, the time that the occlusive device remains inflated is minimized.
In another embodiment of the present invention, a method for treating an intravascular occlusion comprises delivering an occlusive device at its distal end into a blood vessel to a site near said occlusion. A catheter having a proximal end and distal end is delivered to the site of said occlusion such that the distal end of the catheter is proximal to the occlusive device. The occlusive device on the guidewire is actuated at a location distal to said occlusion to at least partially occlude blood flow through the vessel. A drug-containing fluid is delivered from the distal end of the catheter such that at least a portion of the drug-containing fluid contacts the occlusive device.
In another embodiment of the present invention, a method of treating an intravascular occlusion in a blood vessel comprises delivering a guidewire having an occlusive device to the site of the occlusion such that the occlusive device is distal to the occlusion. A catheter is delivered having a proximal end and a distal end and a lumen extending therethrough to the site of the occlusion such that the distal end of the catheter is proximal to the occlusive device. The occlusive device is actuated to at least partially obstruct blood flow through the blood vessel. A treatment fluid is delivered through the lumen of the catheter such that the fluid flows in a proximal to distal direction out of the distal end of the catheter, and then flows in a distal to proximal direction after contacting the occlusive device. Particles generated by the action of the treatment fluid on the occlusion are aspirated through the lumen of the catheter at the distal end.
In another embodiment of the present invention, a method for crossing an intravascular occlusion in a blood vessel is provided. The method comprises delivering a hollow wire in a proximal to distal direction past the occlusion, and delivering fluids through a lumen in said hollow wire to dissolve the occlusion while crossing of the occlusion with the hollow wire.
In another embodiment of the present invention, a method for treating an intravascular occlusion, comprises delivering a catheter having a proximal end and a distal end and a lumen extending therethrough into a blood vessel to a site near said occlusion. The catheter has an occlusive device on the distal end. The occlusive device is actuated at a location distal to the occlusion to at least partially occlude blood flow through said vessel. A drug-containing fluid is injected through the lumen of the catheter across said occlusion in a distal to proximal direction. In one embodiment, the drug-containing fluid is delivered through a plurality of holes in the catheter proximal to the occlusive device. In another embodiment, the drug-containing fluid is delivered through a plurality of holes in a proximal face of an occlusive balloon.
In another embodiment, it is an objection of the present invention to provide an apparatus or an assembly and method which can be used with approved diagnostic and therapeutic devices while minimizing the opportunities for emboli to migrate downstream.
Another object of the present invention is to provide an apparatus or assembly and method of the above character which makes it possible to perform therapeutic procedures without using perfusion.
Another object of the invention is to provide an apparatus or assembly and method of the above character in which the proximal balloon utilized is a balloon carried by a guide wire.
Another object of the invention is to provide an apparatus or assembly and method of the above characters in which the inflation fitting carried by the proximal extremity of the balloon-on-a-wire is removable so that catheters can be slid over the wire without removal of the wire from the site in which it is disposed.
Another object of the present invention is to provide an apparatus or assembly and method for treating occluded vessels of the above character which makes it possible to prevent downstream flow of debris or emboli.
Another object of the invention is to provide an apparatus and method which makes it possible to reverse the flow of blood in an occluded vessel during the time that a stenosis is being crossed.
Another object of the invention is to provide an apparatus and method of the above character in which a negative pressure is created within the vessel to reverse the flow of blood in the vessel.
Another object of the invention is to provide an apparatus and method of the above character in which it is only necessary to stop the flow of blood in a vessel of a patient for a very short period of time.
Another object of the invention is to provide an apparatus and method in which a working space is provided in the vessel free of blood for treatment of the stenosis.
Another object of the invention is to provide an apparatus and method of the above character in which material which is dislodged during the treatment of the occlusion or stenosis is removed by suction.
Another object of the invention is to provide an apparatus and method of the above character in which blood is shunted around the working space.
Another object of the invention is to provide an apparatus and method in which a cutting device is utilized for treatment of the stenosis or atheroma in the vessel and in which the material removed from the stenosis or atheroma is aspirated out of the operating space.
Another object of the invention is to provide an apparatus and method of the above character in which the amount of material removed from the stenosis or atheroma can be precisely controlled.
Another object of the invention is to provide an apparatus and method of the above character which makes it possible to treat stenoses or occlusions in the vessel wnich are normally not accessible for surgical procedures.
Another object of the invention is to provide an apparatus and method of the above character which utilizes two spaced apart balloons to create the working space in the vessel.
Another object of the invention is to provide an apparatus and method of the above character that can be utilized to create a working space in a vessel having a bifurcation therein and in which the working space includes the bifurcation.
Another object of the invention is to provide an apparatus and method of the above character which utilizes three spaced apart balloons to create the working space in the vessel having a bifurcation therein.
Another object of the invention is to provide an apparatus and method of the above character which includes a control console for controlling the inflation of the blood flow pump.
Another object of the invention is to provide an apparatus and method of the above character which is particularly adapted for use with the carotid vessels.
Another aspect of the present invention is that the catheter system itself is provided with occlusive devices to form an emboli containment chamber. It will be noted that at least two such occlusive devices are needed to form a chamber in a straight vessel, while multiple occlusive devices may be necessary to provide emboli containment in the case of a branching vessel. Again, in this context, the term “occlusive device” makes reference to the blocking or containment of emboli within the chamber, since perfusion systems which provide occlusion to the emboli are within the scope of the present invention. Thus, various types of occlusive devices such as filters or expandable braids that allow particles of less than 20 micrometers to pass through while preventing the passage of larger particles, and including inflatable or expendable balloons such as those which are employed by the present catheter system or otherwise, are within the scope of the present invention. In one preferred embodiment, the outer catheter comprises a main catheter having an occlusive balloon mounted on the outer diameter thereof. The occlusive balloon is inflated by means of an inflation lumen formed in a wall of the main catheter. The inner catheter comprises what may be referred to as a guidewire, but which is also hollow to provide an inflation lumen for a second occlusive balloon mounted at the distal section thereof. This occlusive balloon remains inflated until the guide catheter crosses the site of the lesion Within the vessel. Thus, when inflated, these two occlusion balloons form an emboli containment chamber. The inner catheter provides a guidewire for those types of therapy devices which are in common use. One such catheter for a dedicated irrigation/aspiration catheter is positioned over the guidewire to form one of the irrigation/aspiration paths therewith.
In another embodiment, the present invention provides a novel method for containing and removing substances such as emboli from blood vessels. The method is particularly useful in bifurcated vessels, such as the carotid arteries and in other blood vessels above the aortic arch. In one embodiment of the method, there is provided at least one occlusive device such as a balloon or filter, a therapy catheter to treat the occlusion, and a source of aspiration to remove the debris created by the therapy. By utilizing the fluid pressure and flow within the blood vessel, this method can eliminate the need for a separate irrigation catheter and irrigation fluid. Alternatively, irrigation fluid may be provided to flush the area. The minimally invasive treatment allows occlusions to be treated more rapidly and less invasively than known methods, with reduced cost and risk to the patient.
In accordance with one aspect of the present invention, there is provided a method for the treatment of an occlusion in a carotid artery. A main catheter having a first occlusive device on its distal end is inserted into the artery, until the occlusive device is proximal to the occlusion. The first occlusive device is activated to occlude the artery proximal to the occlusion. An inner catheter having a second occlusive device on its distal end is inserted into the artery across the occlusion, until the occlusive device is distal to the occlusion. The second occlusive device is then activated to occlude the artery distal to the occlusion and create a working area surrounding the occlusion. By occlusive device is meant any device which is capable of preventing at least some particles or other debris from migrating downstream. Examples of occlusive devices include inflatable balloons, filters or braids, or other mechanical devices.
According to the foregoing aspect of the invention, a therapy catheter is then inserted into the working area and used to treat the occlusion. Appropriate treatment can include direct drug delivery to the site of the occlusion, angioplasty, cutting, scraping or pulverizing the occlusion, ablating the occlusion using ultrasound or a laser, deploying a stent within the artery, use of a thrombectomy or rheolitic device, or other treatments. Following treatment of the occlusion, the therapy catheter is removed. An aspiration catheter is then delivered to the working area, and the first occlusive device is deactivated to allow blood flow into the working area. Blood flow from collateral vessels prevent the movement of particles and debris downstream where they could cause serious complications. The blood flow also acts as irrigation fluid to create turbulence within the area. Aspiration of the working area is then performed to removed particles and debris. Aspiration can occur simultaneously with the deactivating of the first occlusive device, if desired. Alternatively, either step can be performed first.
In another aspect of the method of the present invention, the occlusive devices are activated and deactivated more than once. After the first occlusive device is deactivated to allow blood flow into the area, the occlusive device is reactivated. The second occlusive device is then deactivated, to allow blood flow in from the distal end of the working area. The second occlusive device is reactivated, and these steps can be repeated any number of times until sufficient irrigation and aspiration of the working area occurs.
In yet another aspect of the method, the first inner catheter with its occlusive device is delivered into one branch of a bifurcated vessel (such as the carotid artery), while a second inner catheter having a third occlusive device on its distal end is delivered into the other branch of the bifurcated vessel to occlude it. Aspiration then occurs in both branches of the artery to remove particles and debris.
In a further aspect of the method, aspiration occurs through the main catheter, and a separate aspiration catheter is not required. Following removal of the therapy catheter, and deactivation of the first occlusive device to allow blood flow into the working area, aspiration occurs through the distal end of the main catheter. This eliminates the need to deliver a separate aspiration catheter, thus saving time which is critical in these types of procedures.
If desired, an irrigation catheter can be delivered into the working area following the removal of the therapy catheter. The irrigation catheter is used to deliver irrigation fluid to the working area. Aspiration then occurs through the distal end of the main catheter. In this case, anatomical irrigation (the use of the patient's own blood flow for irrigation) as described above, is not used.
Yet another aspect of the method may be performed with a single occlusive device. A main catheter or guide catheter is first delivered into the carotid artery, with the distal end positioned just proximal to the occlusion. An inner catheter having an occlusive device on its distal end is then positioned with the occlusive device distal to the occlusion. The occlusive device is activated to occlude the artery distal to the occlusion. A therapy catheter is delivered into the artery until it reaches the occlusion and therapy is performed to reduce or eliminate the occlusion. The therapy catheter is removed, and an intermediate catheter is delivered to a position proximal to the occlusive device. Preferably, the distance between the proximal end of the occlusive device and the distal end of the intermediate catheter is narrowed at one point during aspiration to a distance of about 2 centimeters or less. The area just proximal to the occlusive device is aspirated, using the intermediate catheter, and then irrigated. The aspirating and irrigating steps can be repeated as often as necessary to facilitate the removal of particles and debris.
In another embodiment, the intermediate catheter has two or more lumens, such that aspiration and irrigation occur through different lumens within the same catheter. This prevents the possibility that aspirated particles will be flushed back into the patient when irrigation is begun.
In further aspects of the present invention, two and even three occlusive devices are employed. In the case of two occlusive devices, a main or guide catheter with an occlusive device on its distal end is delivered to the common carotid artery and the occlusive device is activated. Next, an inner catheter with an occlusive device is delivered distal to the occlusion in the internal carotid artery and activated, thus isolating the occlusion between the two occlusive devices. Therapy is performed on the occlusion, followed by aspiration, and irrigation if desired.
When three occlusive devices are used, an occlusive device is activated in the common carotid artery. An inner catheter with an occlusive device is then delivered to the external carotid artery and the occlusive device activated. Next, a second inner catheter is delivered to the internal carotid artery past the site of the occlusion and the occlusive device activated to occlude the internal carotid artery. Alternatively, the first inner catheter and occlusive device is delivered to the internal carotid artery and activated, followed by delivery and activation of the second inner catheter and occlusive device in the external carotid artery. In either case, the occlusion is completely isolated between the three occlusive devices. This is followed by therapy on the occlusion and sequential aspiration and irrigation as desired.
Accordingly, a carotid artery can be treated quickly and efficiently. The patient's own blood can serve as irrigation fluid, thereby eliminating the need for a separate irrigation catheter and supply of irrigation fluid. The working area may be cleaned in an efficient manner by performing repeated activation and deactivation of the occlusive devices surrounding the working area. The catheter-based approach reduces the amount of time required to complete the procedure, and allows normal blood flow in the vessel to be restored in a very short period of time. Use of a minimally invasive procedure reduces risks and trauma to the patient, decreases costs, and improves recovery time.
Another aspect of the invention comprises a method for the treatment of an occlusion in a branch of a bifurcated blood vessel having a common portion and two branches, such as the carotid artery, comprising providing an elongate member having an occlusive device at a distal end portion thereof, delivering the elongate member through the common portion of the bifurcated vessel and into a branch of the bifurcated vessel (such as the internal carotid artery), and positioning the occlusive device in said branch distal of the occlusion. The method further comprises sliding a therapy catheter on the elongate member, occluding said branch only on the distal side of the occlusion by actuating the occlusive device, treating the occlusion with the therapy catheter, and providing a second catheter having a fluid flow lumen in fluid communication with a fluid flow opening at a distal end portion of the second catheter. The method additionally comprises using the occlusive device to occlude said branch of the vessel while: (a) positioning the fluid flow opening of the second catheter in said branch of the vessel at a location between the occlusive device and the treated occlusion; and (b) applying fluid pressure to the fluid flow lumen to cause fluid flow along said branch, between (i) an intersection of said branch with the common portion and (ii) said location, whereby fluid flows across the treated occlusion; and then deactuating the occlusive device.
Still another aspect of the invention comprises a method for the treatment of an occlusion in a branch of a bifurcated blood vessel having a common portion and two branches, such as the carotid artery, comprising providing an elongate member having an occlusive device at a distal end portion thereof, delivering the elongate member through the common portion of the bifurcated vessel and into a branch of the bifurcated vessel (such as the internal carotid artery), positioning the occlusive device in said branch distal of the occlusion, sliding a therapy catheter on the elongate member, and occluding said branch on the distal side of the occlusion by actuating the occlusive device. The method further comprises treating the occlusion with the therapy catheter, removing the therapy catheter from said branch of the vessel, providing a second catheter having a fluid flow lumen in fluid communication with a fluid flow opening at a distal end portion of the second catheter, and sliding the second catheter on the elongate member after the removal of the therapy catheter. The method additionally comprises using the occlusive device to occlude said branch of the vessel while (a) positioning the fluid flow opening of the second catheter in said branch of the vessel at a location between the occlusive device and the treated occlusion; (b) applying fluid pressure to the fluid flow lumen to cause fluid flow along said branch, between (i) an intersection of said branch with the common portion and (ii) said location, whereby fluid flows across the treated occlusion; and then deactuating the occlusive device.
Yet another aspect of the invention comprises a method for the treatment of an occlusion in a branch of a bifurcated blood vessel having a common portion and two branches, such as the carotid artery, comprising providing an elongate member having an occlusive device at a distal end portion thereof, delivering the elongate member through the common portion of the bifurcated vessel and into a branch of the bifurcated vessel (such as the internal carotid artery), positioning the occlusive device in said branch distal of the occlusion, sliding a therapy catheter on the elongate member, occluding said branch only on the distal side of the occlusion by actuating the occlusive device, and treating the occlusion with the therapy catheter. The method further comprises using the occlusive device to occlude the branch of the vessel while: (a) delivering irrigation fluid to a distal end portion of the therapy catheter through an annulus between the therapy catheter and the elongate member; (b) passing the irrigation fluid out of a fluid flow opening in the distal end portion of the therapy catheter; and (c) positioning the fluid flow opening of the therapy catheter in said branch of the vessel at a location near the occlusive device between the occlusive device and the treated occlusion, such that fluid flows across the treated occlusion; and then deactuating the occlusive device.
Still another aspect of the invention comprises a method for the treatment of an occlusion in a branch of bifurcated blood vessel having a common portion and two branches, such as the carotid artery, comprising providing an elongate member having an occlusive device at a distal end portion thereof, delivering the elongate member through the common portion of the bifurcated vessel and into a branch of the bifurcated vessel (such as the internal carotid artery), positioning the occlusive device in said branch distal of the occlusion, positioning an outer catheter so that a portion of the outer catheter is in the common portion of the vessel, sliding a therapy catheter within the outer catheter and on the elongate member, actuating the occlusive device such that it occludes said branch of the vessel, and treating the occlusion with the therapy catheter. The method further comprises using the occlusive device to occlude the branch of the vessel while (a) delivering irrigation fluid to a distal end portion of the outer catheter; (b) passing the irrigation fluid out of a fluid flow opening in the distal end portion of the outer catheter; (c) positioning the fluid flow opening of the outer catheter in said branch of the vessel at a location between the occlusive device and the treated occlusion, such that fluid flows across the treated occlusion; and then deactuating the occlusive device.
Still another aspect of the invention comprises a method for treatment of an occlusion in a branch of a bifurcated blood vessel having a common portion and two branches, comprising positioning an occlusive device distal of the occlusion to occlude said branch of the vessel, treating the occlusion using a therapy device, delivering irrigation fluid between the occlusion and the occlusive device such that irrigation fluid flows across the treated occlusion towards an intersection of said branch and the common portion, wherein emboli in said branch are carried to the intersection, and allowing anatomical blood flow in the common portion to carry the emboli through another of the branches.
Yet another aspect of the invention comprises a method for the treatment of an occlusion in a blood vessel, such as the carotid artery, comprising providing an inner catheter comprising an elongate member having an occlusive device at a distal end portion thereof, delivering the elongate member through the vessel, positioning the occlusive device distal of the occlusion, sliding a therapy catheter on the elongate member, actuating the occlusive device such that it occludes the vessel, and treating the occlusion with the therapy catheter. The method further comprises uses the occlusive device to occlude the vessel while: (a) delivering irrigation fluid through the elongate member; (b) passing the irrigation fluid out of a fluid flow opening in the occlusive device such that fluid flows across the treated occlusion; and then deactuating the occlusive device. Still another aspect of the invention comprises a method of performing a medical procedure in a blood vessel using an expandable member which seals against walls of the blood vessel in response to application of an expansion force through a range of vessel diameters up to a maximum diameter beyond which sealing will not occur in the vessel, in which the method comprises positioning the expandable member in a selected blood vessel distal to an occlusion to be treated at a location where the vessel diameter is at least 20% less than said maximum diameter, applying an expansion force to cause the expandable member to expand into sealing contact with walls of the selected vessel at said location, and treating the occlusion while the expandable member is expanded, whereby the expandable member seals against walls of the selected vessel even if the diameter of the selected vessel at said location increases to said maximum diameter as a result of the treatment.
Another aspect of the invention comprises a method of treating an occlusion in a blood vessel, comprising positioning an expandable member distal to the occlusion to be treated, performing therapy on the occlusion, and using the expandable member to block migration of emboli created as a result of the therapy, while allowing blood to flow from one side to another side of the expandable member in a proximal to distal direction. The method further comprises positioning a fluid port of a catheter between the treated occlusion and the expandable member, and applying suction to the fluid port to aspirate fluid into the catheter while the fluid port is positioned between the treated occlusion and the expandable member.
Still another aspect of the invention comprises a method of treating an occlusion in a blood vessel, comprising positioning an expandable member distal to the occlusion to be treated, performing therapy on the occlusion, and using the expandable member to block migration of emboli created as a result of the therapy, while allowing blood to flow past the expandable member in a proximal to distal direction. The method further comprises positioning a fluid port of a catheter between the treated occlusion and the expandable member, delivering irrigation fluid through the fluid port, and using the irrigation fluid to provide fluid flow across the treated occlusion in a distal to proximal direction.
Yet another aspect of the invention comprises a method of treating an occlusion in a blood vessel, comprising positioning an expandable member distal to the occlusion to be treated, using a therapy balloon to perform therapy on the occlusion, using the expandable member to block migration of emboli created as a result of the therapy, while allowing blood to flow from one side to another side of the expandable member in a proximal to distal direction. The method further comprises using the therapy balloon to occlude the blood vessel at a location distal to the treated occlusion, positioning a fluid port of a catheter between the treated occlusion and said location, and providing fluid flow through the fluid port such that said fluid flows across the treated occlusion.
FIGS. 61A-H illustrate the use of the catheters of the present invention in emboli containment treatment procedures.
Certain preferred embodiments of the present invention provide methods for localized drug delivery in high concentration to the site of an intravascular occlusion by using an aspiration catheter for both aspiration and drug delivery. This method is used either alone, or in combination with a therapy catheter as discussed below. The drug delivery method may be used in conjunction with any method for preventing distal embolization during removal of plaque, thrombi or other occlusions from a blood vessel. A preferred embodiment of the present invention is adapted for use in the treatment of a stenosis or an occlusion in a blood vessel in which the stenosis or occlusion has a length and a width or thickness which at least partially occludes the vessel's lumen. Thus, the method is effective in treating both partial and complete occlusions of blood vessels.
It is to be understood that “occlusion” as used herein with reference to a blood vessel is a broad term and is used in its ordinary sense and includes both complete and partial occlusions, stenoses, emboli, thrombi, plaque and any other substance which at least partially occludes the lumen of the blood vessel. The term “occlusive device” as used herein is a broad term and is used in its ordinary sense and includes balloons, filters and other devices which are used to partially or completely occlude the blood vessel prior to performing therapy on the occlusion. It will be appreciated that even when a filter is used, the filter may be partially or completely occlusive.
The term “drugs” as used herein is a broad term and is used in its ordinary sense and includes genes and cells. The methods of the present invention are particularly suited for use in removal of occlusions from saphenous vein grafts, coronary and carotid arteries, and vessels having similar pressures and flow.
A. Balloon System
B. Syringe Assembly
Preferred embodiments of the present invention may comprise or be used in conjunction with a syringe assembly as described in U.S. Pat. No. 6,234,996, the entirety of which is incorporated herein by reference in its entirety. One preferred syringe assembly is available from Medtronic PercuSurge, Inc. of Sunnyvale, Calif. under the name EZ FLATOR™.
One preferred embodiment of a syringe assembly 22 for inflation and deflation of an occlusion balloon is shown in
C. Occlusion Balloon Guidewire
The occlusion balloon guidewire system generally illustrated in
As shown in
A valve 24, as described below, is inserted into the proximal end 46 of the tubular body 44 to control inflation of a balloon 12 mounted on the distal end of the tubular body through inflation notch 52. The inflation notch 52 is preferably formed by electric discharge machining (EDM). A proximal marker 53, which is preferably made of gold, is placed over the tubular body 44 distal to the inflation notch 52. Distal to the marker 53, a nonuniform coating 55 of polymer material, more preferably polytetrafluoroethylene (TFE), is applied to the tubular body 44, terminating proximal to a shrink tubing 62. The shrink tubing 62 extends up to and within the balloon 12, as described below. Adhesive tapers 72 and 74 extend from the proximal and distal ends of the balloon, respectively. The proximal taper 72 preferably extends from the proximal end of the balloon to the shrink tubing 62 on the tubular body 44, while the distal taper 74 extends to coils 56 extending from the distal end 48 of the tubular body 44. The coils 52 terminate in a distal ball 58.
The length of the tubular body 44 may be varied considerably depending on the desired application. For example, when catheter 14 serves as a guidewire for other catheters in a conventional percutaneous transluminal coronary angioplasty procedure involving femoral artery access, tubular body 44 is comprised of a hollow hypotube having a length in the range from about 160 to about 320 centimeters, with a length of about 180 centimeters being optimal for a single operator device, or 300 centimeters for over the wire applications. Alternatively, for a different treatment procedure not requiring as long a length of tubular body 44, shorter lengths of tubular body 44 may be provided.
Tubular body 44 generally has a circular cross-sectional configuration with an outer diameter within the range from about 0.008 inches to 0.14 inches. In applications where catheter 14 is to be used as a guidewire for other catheters, the outer diameter of tubular body 44 ranges from 0.010 inches to 0.038 inches and preferably is about 0.014 to 0.020 inches in outer diameter or smaller. Noncircular cross-sectional configurations of lumen 50 can also be adapted for use with the catheter 14. For example, triangular, rectangular, oval and other noncircular cross-sectional configurations are also easily incorporated for use with the preferred embodiments, as will be appreciated by those of skill in the art. The tubular body 44 may also have variable cross-sections.
The tubular body 44 has sufficient structural integrity or “pushability” to permit catheter 14 to be advanced through the vasculature of a patient to distal arterial locations without buckling or undesirable kinking of tubular body 44. It is also desirable for the tubular body 44 to have the ability to transmit torque such as in those embodiments where it may be desirable to rotate tubular body after insertion into a patient. A variety of biocompatible materials known by those of skill in the art to possess these properties and to be suitable for catheter manufacture may be used to produce tubular body 44. For example, tubular body 44 may be made of a stainless steel material such as ELGILOY™. or may be made of polymeric material such as PEEK, nylon, polyimide, polyamide, polyethylene or combinations thereof. In one preferred embodiment, the desired properties of structural integrity and torque transmission are achieved by forming the tubular body 44 out of an alloy of titanium and nickel, commonly referred to as nitinol. In a more preferred embodiment, the nitinol alloy used to form the tubular body 80 is comprised of about 50.8% nickel and the balance titanium, which is sold under the trade mark TINEL™ by Memry Corporation. It has been found that a catheter tubular body having this composition of nickel and titanium exhibits an improved combination of flexibility and kink-resistance in comparison to other materials.
Other details regarding construction of balloon guidewire catheters may be found in assignee's U.S. Pat. Nos. 6,068,623, 6,228,072, and copending applications entitled FLEXIBLE CATHETER, application Ser. No. 09/253,591, filed Feb. 22, 1999, now U.S. Pat. No. 6,500,147, and FLEXIBLE CATHETER WITH BALLOON SEAL BANDS, application Ser. No. 09/653,217, filed Aug. 31, 2000, now abandoned, all of which are hereby incorporated by reference in their entirety. One preferred guidewire system is available from Medtronic PercuSurge, Inc. of Sunnyvale, Calif., under the name GUARDWIRE PLUS™.
As illustrated in
The balloon 12 described in the preferred embodiments preferably has a length of about 5 to 9 mm and more preferably about 6 to 8 mm. Other occlusive devices such as filters are suitable for the catheter 44, such as those disclosed in assignee's copending applications entitled OCCLUSION OF A VESSEL, Ser. No. 09/026,106, filed Feb. 19, 1998, now U.S. Pat. No. 6,312,407, OCCLUSION OF A VESSEL, Ser. No. 09/374,741, filed Aug. 13, 1999, now abandoned, OCCLUSION OF A VESSEL AND ADAPTER THEREFOR, Ser. No. 09/509,911, filed Feb. 17, 2000, now abandoned, MEMBRANES FOR OCCLUSION DEVICE AND METHODS AND APPARATUS FOR REDUCING CLOGGING, Ser. No. 09/505,554, filed Feb. 17, 2000, now abandoned, and STRUT DESIGN FOR AN OCCLUSION DEVICE, Ser. No. 09/505,546, filed Feb. 17, 2000, now abandoned, the entirety of each of which is hereby incorporated by reference.
With reference to
In one embodiment, shown in
D. Inflation Adapter and Low Profile Catheter Valve
Referring next to
As shown in
It will be emphasized that other types of adapters and/or valves can be employed with the inflation syringe and/or syringe assembly described herein, in order to achieve rapid and accurate inflation/deflation of medical balloons or other non-balloon medical devices. Therefore, although the preferred embodiments are illustrated in connection with a low volume occlusion balloon 12, other types of balloons and non-balloon devices can benefit from the advantages of the invention described herein.
As shown in
Preferably, the catheter 14 is positioned within the housing of the adapter 20 with the valve closed, such that the side inflation port 52 is located in the sealed inflation area 92 of the housing. The catheter 14 is then positioned in the second half 82 of the adapter 20. A distal portion of the catheter 14 extends out of the housing and into the patient, and a proximal portion of the catheter including the catheter valve 24 extends out of the other side of the adapter 20. The adapter is closed, the locking clip 84 is secured, and a syringe assembly is attached. The actuator 94 is moved from a first position to a second position, such that the sliding panels 98 within the housing cause the valve 24 to be in an open position to allow fluid flow through the inflation port 52. A syringe assembly 22 is then used to inflate the balloon 12. Closing the valve 24 is accomplished by moving the actuator 96 from the second position back to the first position, such that the balloon inflation is maintained. Once the valve is closed the adapter may be removed and treatment and other catheters may be delivered over the guidewire.
Other inflation adapter/inflation syringe assemblies may also be used. Also, the adapter 20 can have additional features, such as a safety lock provided on the actuator knob 94 to prevent accidental opening when the adapter is being used and the catheter valve is open. In addition, the adapter can be provided with an overdrive system to overdrive a sealing member into a catheter. Details of these features and other inflation assemblies may be found in assignee's U.S. Pat. No. 6,050,972 and copending applications, SYRINGE AND METHOD FOR INFLATING LOW PROFILE CATHETER BALLOONS, application Ser. No. 09/025,991, filed Feb. 19, 1998, now abandoned, and LOW VOLUME SYRINGE AND METHOD FOR INFLATING SURGICAL BALLOONS, application Ser. No. 09/195,796, filed Nov. 19, 1998, now abandoned, all of which are incorporated by reference in their entirety.
E. Aspiration Catheter
The occlusion system described above advantageously enables an exchange of catheters over a guidewire while an occlusive device isolates particles within the blood vessel. For example, a therapy catheter can be delivered over the guidewire to perform treatment, and then be exchanged with an aspiration catheter to remove particles from the vessel. Further details of this exchange are described in assignee's copending application entitled EXCHANGE METHOD FOR EMBOLI CONTAINMENT, Ser. No. 09/049,712, filed Mar. 27, 1998, now U.S. Pat. No. 6,544,276, the entirety of which is hereby incorporated by reference.
An aspiration catheter according to one preferred embodiment of the present invention is shown in
The dual lumen tubing 216 preferably defines two lumens, one for aspiration and the other for a guidewire to pass therethrough. More particularly, the lumen that the elongate body 206 is inserted into acts as the aspiration lumen, being in fluid communication with the lumen of the elongate tubular body 206. The aspiration lumen preferably ends in a distal aspiration mouth 222, which preferably defines an oblique opening. Aspiration therefore occurs through both the lumen of the elongate tubular body 206 and the aspiration lumen of the dual lumen tubing.
The guidewire lumen is provided adjacent the aspiration lumen in the dual lumen tubing and has a proximal end 224 preferably distal to the proximal end 218 of the aspiration lumen of the dual lumen tubing, and a distal end 226 preferably distal to the aspiration mouth 222. A marker 228 is placed within the guidewire lumen at the distal end of the aspiration mouth. Additional markers 230, 232 may also be placed over the elongate body 206 and/or support sheaths. Further details regarding these and other aspiration catheters are provided below and in Applicant's copending applications entitled ASPIRATION CATHETER, Ser. No. 09/454,522, filed Dec. 7, 1999, now U.S. Pat. Nos. 6,849,068, and 6,152,909, the entirety of both of which are hereby incorporated by reference.
In a preferred embodiment of the invention, an occlusion balloon guidewire 14 such as described above is delivered to the site of an occlusion in a blood vessel. In one embodiment (not shown), a guide catheter is first introduced into the patient's vasculature through an incision made in the femoral artery in the groin and is used to guide the insertion of the guidewire and/or other catheters and devices to the desired site. The guidewire is then advanced until its distal end reaches a site proximal to the occlusion. Fluoroscopy is typically used to guide the guidewire and other devices to the desired location within the patient. The devices are frequently marked with radiopaque markings to facilitate visualization of the insertion and positioning of the devices within the patient's vasculature. It should be noted that at this point, blood is flowing through the vessel in a proximal to distal direction. The guide catheter may then be removed, or alternatively, may be used as the aspiration catheter itself, as described below.
A. Aspirating While Crossing the Occlusion
In one embodiment, aspiration is performed while advancing a guidewire across the site of the occlusion in a proximal to distal direction to prevent distal embolization. An aspiration catheter, such as described below, is delivered over the guidewire to a site just proximal to the site of the occlusion, and, while aspirating, the occlusion in the vessel is crossed with both the guidewire and the aspiration catheter in a proximal to distal direction. Further details of this method are described in assignee's copending application entitled METHODS FOR REDUCING DISTAL EMBOLIZATION, Ser. No. 09/438,030, filed Nov. 10, 1999, now U.S. Pat. No. 6,652,480, and in U.S. Pat. No. 5,833,650, the entirety of both of which are hereby incorporated by reference. The term “aspiration catheter” is intended to include any elongated body having a lumen which can be used to withdraw particles, fluid or other materials from a blood vessel. Any such device can be attached to a suction apparatus for removal of intravascular particles.
In one embodiment, the distal tip of the aspiration catheter is no more than about 2 cm, in another embodiment no more than about 0.5-1 cm, behind or proximal to the distal tip of the guidewire during crossing. In yet another embodiment, the distal end of the aspiration catheter is then moved in a distal to proximal direction across the occlusion, while continuously aspirating. This process ensures the removal of any particles which may be created during the delivery of the guidewire to a position distal to at least a portion of the occlusion. Aspiration from proximal to distal, and distal to proximal, can be repeated as many times as necessary to completely aspirate all particles. These procedures are all preferably performed prior to occlusion of the vessel at a site distal to the occlusion with the occlusion device, and prior to treatment of the occlusion. It should be noted that, as used herein, “proximal” refers to the portion of the apparatus closest to the end which remains outside the patient's body, and “distal” refers to the portion closest to the end inserted into the patient's body.
As the guidewire and aspiration catheter cross the occlusion, blood and/or other fluid enters the vessel and keeps any particles dislodged during the procedure from flowing in a distal to proximal direction. In addition, the blood pressure and flow provides the irrigation necessary for aspiration. The blood pressure in the vessel is preferably at least about 0.2 psi, and the vessel is capable of providing a flow rate of at least about 5 cc per minute when not occluded.
B. Drug Delivery
In a drug or fluid delivery embodiment of the present invention, after the distal end of the guidewire having an occlusive device such as a balloon or filter is delivered past the site of the occlusion and the optional aspiration step is complete, the occlusive device is actuated to at least partially, an in one embodiment totally, occlude the vessel at a site distal to the site of the occlusion. In another embodiment, prior to actuation of the occlusive device, a first therapy or other catheter is delivered over the guidewire. Once the blood vessel is occluded, therapy can be performed by delivering a drug or fluid through a catheter advanced over the guidewire to the site of the occlusion as described herein to partially or totally dissolve the occlusion. After therapy has been performed, aspiration of any particles broken off from the occlusion may also be performed while the occlusive device is actuated. It will be appreciated that it may take time for the drug to dissolve or act on the occlusion, and therefore a clinician may wait a desired period before aspirating.
Various thrombolytic or other types of drugs can be delivered locally in high concentrations to the site of the occlusion via a therapy catheter. It is also possible to deliver various chemical substances or enzymes via a therapy catheter to the site of the stenosis to dissolve the obstruction. The therapy catheter can be any of a number of devices that may or may not ride over the guidewire, including a balloon catheter used to perform angioplasty, a catheter which delivers a stent, an atherectomy device, a laser or ultrasound device used to ablate the occlusion and similar devices. Drug delivery using a therapy catheter is shown in
Referring to
Thus, as illustrated in
In the embodiment where an aspiration catheter 200 aspirates while the guidewire 14 crosses the occlusion 18 as described above, when the occlusive device is actuated the aspiration catheter is already delivered to the site of the occlusion over the guidewire. It will also be appreciated, however, that the guidewire 14 may cross the occlusion 18 without aspirating simultaneously. In this embodiment, the aspiration catheter 200 may be delivered after the guidewire crosses the occlusion. The aspiration catheter is then preferably delivered until it is proximal to the occlusion 18 before the occlusive device such as a balloon is actuated. By actuating the occlusive device before the aspiration catheter crosses the occlusion, the risk of particles migrating downstream during crossing of the occlusion by the aspiration catheter is eliminated. Alternatively, if there is minimal risk that the crossing of the aspiration catheter will break off particles, the occlusive device can be actuated after the aspiration catheter crosses the occlusion 18. As shown in
One embodiment relates to localized delivery of high concentrations of a thrombolytic, anticoagulant or restenosis-inhibiting drug through the lumen of the aspiration catheter, to promote dissolution of the occlusion and restoration of blood flow through the blood vessel. The fluid containing the drug which is delivered from the aspiration catheter travels in a proximal to distal direction out of the lumen of the aspiration catheter, as indicated by arrows 234 in
Thrombolytic agents contemplated for use in the preferred embodiments of the present invention include, but are not limited to, tissue plasminogen activator (t-PA), streptokinase. Anticoagulants include heparin, hirudin and coumadin. In addition, solutions such as phosphate-buffered saline (PBS), lactated Ringer's solution, or any other pharmaceutically acceptable solution may be used to deliver a radioisotope to the site of an occlusion which has been treated with a therapy catheter to inhibit restenosis of the occlusion. These radioisotopes, including beta-emitters (e.g., 32p) and gamma-emitters (e.g., 131I), and any other medically acceptable radioisotopes well known in the art, permanently damage the treated occlusion and prevent tissue regrowth.
Other therapeutic or other agents that may be used include, but are not limited to, thrombin inhibitors, antithrombogenic agents, fibrinolytic agents, cytostatic agents, vasospasm inhibitors, calcium channel blockers, vasodilators, antihypertensive agents, antimicrobial agents, antibiotics, inhibitors of surface glycoprotein receptors, antiplatelet agents, antimitotics, microtubule inhibitors, anti secretory agents, actin inhibitors, remodeling inhibitors, antisense nucleotides, antimetabolites, antiproliferatives, anticancer chemotherapeutic agents, anti-inflammatory steroid or non-steroidal anti-inflammatory agents, immunosuppressive agents, growth hormone antagonists, growth factors, dopamine agonists, radiotherapeutic agents, peptides, proteins, enzymes, extracellular matrix components, inhibitors, free radical scavengers, chelators, antioxidants, anti polymerases, antiviral agents, photodynamic therapy agents, and gene therapy agents.
In one embodiment, the drug is delivered through the lumen of the aspiration catheter at a flow rate of between about 0.1 cc/sec and 10 cc/sec, in another embodiment, about 0.5 to 2 cc/sec, and in yet another embodiment, about 0.5 cc/sec to 1 cc/sec. In another embodiment, the tip of the aspiration catheter is placed about 0.5 mm to 10 mm, more preferably about 1 mm to 5 mm, from the surface of the occlusive device. Localization of the tip of the aspiration catheter close to the occlusive device 12 creates a more isolated area for drug treatment of the occlusion. In one embodiment, when the tip of the aspiration catheter is close to the surface of the occlusive device, the fluid containing the drug replaces the column of blood distal to the catheter tip, resulting in proximal to distal movement of the fluid containing the drug which replaces the column of blood distal to the catheter tip. In contrast, if the tip of the catheter is placed too far proximal to the occlusive device, the fluid containing the drug cannot move forward out of the catheter due to the force exerted by the column of blood distal to the catheter tip.
In another embodiment, when the drug delivered through the lumen of the aspiration catheter is released at a rapid rate, the drug moves in a proximal to distal direction toward the occlusive device. Once the drug reaches the occlusive device, at least a portion of the drug bounces against the occlusive device and moves in a distal to proximal direction. This localizes the drug at a location proximal to the occlusive device.
After drugs are delivered through the aspiration catheter 200, emboli or other particles 236 may be formed in the vessel as shown in
The aspiration catheter, as shown in
C. Irrigation Catheters
It will be appreciated that when the occlusion in the vessel is too large, it is often desirable to create some space to move past the occlusion prior to delivering the guidewire 14 having the occlusive device. To do this, a guidewire 14 without a balloon or other occlusive device may be used which contains side ports 240 near the distal end and/or an irrigation hole 242 at its distal end, as shown in
In another embodiment, after the guidewire has cleared some space, the guidewire is exchanged for a guidewire having an occlusive device as described above. Further details regarding this type of exchange are described in U.S. Pat. No. 6,159,195, the entirety of which is hereby incorporated by reference. In addition, if an aspiration catheter is already provided on the guidewire, the aspiration catheter itself may be used for the exchange.
Once the guidewire having an occlusive device is delivered, the vessel is then treated such as described above. For instance, an aspiration catheter may be used as described above to deliver drugs to dissolve the occlusion, followed by aspiration. These procedures preferably occur while the balloon on the catheter is inflated. The aspiration catheter is then removed and, optionally, the therapy catheter is inserted to perform therapy, the therapy catheter is removed and the aspiration catheter is delivered to aspirate the particles resulting from the therapy.
In another embodiment shown in
In this embodiment, the proximal end 322 of the conduit 320 is preferably connected to a gas source (not shown), while the distal end 324 is connected to the balloon member 318 through an inlet port 328 in the distal end 310 of the hypotube 304. The distal end 324 of the conduit 320 and the inlet port 328 are sealably connected to each other by suitable means such as adhesive to avoid any gas leak. In this arrangement, the inner lumen 326 of the conduit 320 connects the gas source to the balloon member 318 so that the gas from the gas source can inflate the balloon member 318.
The conduit 320 is preferably made of a flexible material such as polyimide, polyamide, or the like alloy and is in the form of hypotubing. Preferably, the outer diameter of the conduit 320 is significantly smaller than the inner diameter of the lumen 312 of the hypotube 304 so that fluid in the lumen 312 can flow without any restriction. In this embodiment, carbon dioxide (CO2) gas is preferably employed to inflate balloon member 318. In fact, (CO2) gas easily dissolves in blood and does not cause any harm in the patient's body, if an accidental leak occurs. If desired, however, the balloon member may be inflated using any of a number of harmless gases or fluids, or possible combinations thereof. In applications, the irrigation catheter 302B may function as the catheter 302A in the first embodiment. However, with the inflatable balloon member 318, the catheter 302B can be advantageously used for occlusion and irrigation therapies.
As shown in
In application, any pressure over this threshold pressure breaks open these membranes 332, i.e., activates valves 332, and delivers the irrigation fluid, through perforations 314, into the body locations. The fluid delivery can be also provided through leakages from both optional slits (not shown) in the balloon member 318 and the gaps between the coil turns 316. As in the previous embodiment, the catheter 302C can be advantageously used for occlusion and irrigation therapies.
A main catheter 406, with or without a distal occlusive device, is introduced into the patient's vasculature through an incision in the femoral artery in the groin of the patient or through direct access to the arteries in the neck. The main catheter 406 is guided through the vasculature until it reaches the common carotid artery 404, where it can remain in place throughout the procedure.
Once the main catheter 406 is in place proximal to the occlusion 410, an inner catheter or guidewire 420 having an occlusive device 422 at its distal end is delivered through the main catheter 406 into the internal carotid artery 400 and past the site of the occlusion 410. Alternatively, a detachable occlusive device can be deployed at the site distal to the occlusion, and the delivery device removed. In this example, the occlusive device 422 is an inflatable balloon. The balloon is inflated to occlude the internal carotid artery 400 at a site distal to the occlusion 410. It should be understood that the occlusion within the artery can be in a discrete location or diffused within the vessel. Therefore, although placement of the distal occlusive device is said to be distal to the occlusion to be treated, portions of the diffuse occlusion may remain distal to the occlusive device.
The occlusive device 422 preferably may be used to flush fluid across the occlusion 410. In one embodiment, the fluid may be saline solution or another suitable flushing solution. In another embodiment, the fluid may be any one of a number of drugs such as described above. The fluid may be advantageously passed through a lumen in the guidewire 420 and into the occlusive device 422. The occlusive device 422 has at least one fluid flow opening and is preferably microporous on its proximal end, having a plurality of holes 450 (e.g., 10-50) that are preferably less than 1000 microns in diameter and more preferably between 50 and 100 microns in diameter. The holes may be formed in the occlusive device 422 by laser drilling, for example. As fluid passes through the occlusive device 422 and into the internal carotid 400, emboli, particulates, and other debris are flushed past the treated occlusion 410 and down the external carotid 402. In embodiments where the occlusion is not formed near the branching of two vessels, the fluid may be isolated across the occlusion as it flows in a proximal direction away from the balloon. Thus, when the fluid used is a drug as described above, the drug is preferably localized across the occlusion for treatment.
Fluid flow may be maintained with a pressurized syringe or other suitable inflation device, as described above, located outside the patient. The fluid is used for inflating the occlusive device 422 as well as for irrigating emboli from the internal carotid 400 down the external carotid 402, or for localizing drugs across the occlusion.
Another irrigation device and method is disclosed in
Instead of pumping irrigation fluid through the holes 460 as shown in
Fluid flow rates for the methods disclosed in
Further details regarding the devices of
The preferred methods of the invention can be used especially following myocardial infarction, for totally occluded vessels and partially occluded vessels defined by TIMI 0-1 flow, and having no major side branch. However, the method is not intended to be limited only to such applications, and may also be used for vessels having blood flow through side branches. TIMI stands for “thrombolysis in myocardial infarction.” This value is measured angiographically by injecting a dye and noting the time it takes to clear through the blood vessel. A TIMI of 3 means that the vessel is open. A TIMI of 0 means that the vessel is totally occluded. In a totally occluded vessel, one cannot visualize past the site of the occlusion because the dye will not flow past the occlusion. Because the site cannot be visualized, a distal occlusive device generally cannot be used unless the occlusion is dissolved using methods such as described above.
D. Treatment Methods Described in U.S. application Ser. No. 08/650,464
In general, the catheter apparatus is for treatment of a stenosis in a lumen in a blood carrying vessel. It is comprised of a main catheter and a balloon-on-a-wire device. The main catheter is comprised of a first flexible elongate tubular member having proximal and distal extremities. A first inflatable elastic balloon having an interior is coaxially mounted on the distal extremity of the first flexible elongate tubular member. The first flexible elongate tubular member has a balloon inflation lumen therein in communication with the interior of the first balloon. The first elongate tubular member has a main lumen therein extending from the proximal extremity to the distal extremity and exiting through the distal extremity. An adapter is mounted on the proximal extremity of the first flexible elongate tubular member and has a balloon inflation port in communication with the balloon inflation lumen, a therapeutic catheter port and an aspiration port in communication with the main lumen. The balloon-on-a-wire device is comprised of a guide wire having proximal and distal extremities.
A second inflatable elastic balloon has an interior and is coaxially mounted on the distal extremity of the guide wire. The guide wire has a balloon inflation lumen therein in communication with the interior of the second balloon. The balloon-on-a-wire device is slidably mounted in the therapeutic catheter port and in the main lumen of the first elongate tubular member with the proximal extremity of the guide wire being disposed outside of the main lumen. Removable valve means is carried by the proximal extremity of the guide wire and has the capability of forming a fluid-tight seal with respect to the guide wire while permitting relative axial movement of the guide wire and the first flexible elongate tubular member with respect to each other whereby the first balloon can be moved so that it is proximal of the stenosis and the second balloon so that it is distal of the stenosis. The removable valve means includes an inflation port in communication with the balloon inflation lumen and the guide wire. The apparatus is also comprised of means coupled to the balloon inflation port of the first flexible elongate tubular member for inflating the first balloon and means coupled to the balloon inflation port of the removable valve means for inflating the second balloon to create a working space which brackets the stenosis.
More particularly as shown in
The tubular member 516 is provided with a large centrally disposed or main lumen 521 extending from the proximal extremity 517 to the distal extremity 518. It is also provided with a balloon inflation lumen 522 which has a distal extremity in communication with the interior of the first balloon 519 through a port 523. The proximal extremity of the balloon inflation lumen 522 is in communication with a balloon inflation fitting 524 mounted on the proximal extremity 517 of the tubular member 516. The fitting 524 can be of a conventional type as for example a Luer-type fitting which is adapted to be connected to a balloon inflation device (not shown) for inflating and deflating the first balloon 519.
The first tubular member 516 is also provided with an aspiration lumen 526 which exits through the distal extremity 518 and the proximal extremity 517 of the tubular member 516. A Luer-type fitting 527 is mounted on the proximal extremity 517 and is in communication with the aspiration lumen 526. The fitting 527 is adapted to be connected to a suitable aspiration or suction source (not shown) of a conventional type such as a syringe or rubber bulb for aspiration purposes as hereinafter described.
The catheter assembly or apparatus 511 also consists of a second elongate flexible tubular member 531 having proximal and distal extremities 532 and 533. A second inflatable balloon 536 of the same type as the first inflatable balloon is coaxially mounted on the distal extremity 533 in a conventional manner. The tubular member 531 is provided with a large generally centrally disposed arterial blood flow lumen 537 which opens through the distal extremity 533 and is in communication with a Luer-type fitting 538 which as hereinafter described is adapted to be connected to a supply of arterial blood from the patient which for example can be taken from another femoral artery of the patient by the use of a blood pump.
The second tubular member 531 is also provided with a balloon inflation lumen 539 which is in communication with the interior of the second inflatable balloon 536 through a port 541. The proximal extremity of the lumen 539 is in communication with the Luer-type fitting 542 mounted on the proximal extremity 532 of the second tubular member 531 and as with the balloon inflation fitting 524 is adapted to be connected to a balloon inflation-deflation device (not shown) of a conventional type. The second tubular member 531 is also provided with a lumen 543 which also can be used as a guide wire and/or for introducing a saline solution extending from the proximal extremity to the distal extremity. The lumen 543 is sized so that it is adapted to receive a conventional guide wire 546 as for example a 0.014″ or 0.018″ guide wire and extends from the proximal extremity to the distal extremity so that the guide wire 546 can extend beyond the distal extremity of the second tubular member 531. A fitting 547 is provided on the proximal extremity 532 in communication with the lumen 543 for introducing the saline solution.
As shown in
The catheter assembly or apparatus 511 also consists of a third elongate flexible tubular member 551 having proximal and distal extremities 552 and 553. It is provided with a centrally disposed lumen 556 extending from the proximal extremity 552 to the distal extremity 553 and through which the second tubular member 531 is coaxially and slidably mounted.
Means 557 is provided on the distal extremity 553 of the third tubular member 551 for performing a medical procedure. In the embodiment of the invention shown in
The operation and use of the catheter assembly or apparatus 511 in the method of the present invention for treating occluded vessels may now be briefly described in connection with an occlusion formed by a stenosis in a vessel not having a bifurcation therein as for example in saphenous graft or in one of the right and left carotid arteries, also called internal and external carotid arteries, of a patient in connection with the illustrations shown in
After the guiding catheter has been appropriately positioned, the guide wire 546 is introduced separately into the guiding catheter or along with the catheter assembly 511. The distal extremity of the catheter apparatus or assembly 511 with all of the first, second and third balloons 519, 536 and 558 completely deflated, is introduced into the guiding catheter 563 along with or over the guide wire 546 and is advanced through the guiding catheter 563 into the ostium 566 of the carotid artery or vessel 567 and into the lumen or passageway 568 of the vessel as shown in
The distal extremity of the catheter assembly 511 is advanced until it is just proximal of a stenosis 569 in the carotid artery 567 to be treated. The balloon 519 is then inflated by introducing a suitable inflation medium such as a radiopaque liquid into the fitting 524 to cause it to pass through the balloon inflation lumen 522 through the port 523 and into the interior of the first balloon 519 to inflate the same as shown in
While a reverse flow of blood is occurring in the vessel 567, the guide wire 546 is advanced through the stenosis 569 as shown in
With the guide wire 546 remaining in position, the second elongate flexible tubular member 531 with the second balloon 536 thereon in a deflated condition is advanced over the guide wire 546 through the stenosis 569 until the second balloon 536 is distal of the stenosis 569 as shown in
Prior to, during or after inflation of the second balloon 536, the guide wire 546 can be removed. However, it is preferable to remove the guide wire 546 as soon as the second balloon 536 has been advanced so that it is beyond the stenosis 569. At this time, and certainly prior to complete inflation of the second balloon 536, blood is shunted across the stenosis 569 and into the lumen 568 distal of the second balloon 536 by introducing blood through the fitting 538 and into the centrally disposed blood flow lumen 537 in the second tubular member 531 so that it exits out the central lumen 537 distal of the second balloon 536. The blood which is supplied to the fitting 537 can be taken from another femoral artery of the patient and pumped into the fitting 538. In addition, if desired, the blood which is aspirated in the space distal of the first balloon 519 can be appropriately filtered and also supplied to the fitting 538. By shunting blood past the stenosis 569 in this manner it can be seen that blood is being continuously supplied to the carotid artery of the patient during the time that the second balloon 536 is inflated and occludes the lumen 568 in the vessel 567.
As soon as the second balloon 536 has been inflated, it can be seen that there is provided a working space 576 (
Assuming that it is desired to compress the plaque or material forming the stenosis 569 to provide a larger lumen, opening or passageway through the stenosis 569 the third tubular member 551 can be advanced by grasping the proximal extremity 552 to cause the distal extremity with the third balloon 558 thereon to be advanced into the working space 576. As soon as the balloon 558 has been properly positioned within the stenosis 569, the balloon 558 also can be inflated with a suitable inflation medium as for example a radiopaque liquid. The balloon 558 can be inflated to the desired pressure to cause compression of the plaque of the occlusion against the sidewall of the vessel 567 by the application of appropriate pressure. As in conventional angioplasty procedures, the third balloon 558 can be formed of a non-elastic relatively non-compliant material so that high pressures as for example 10-15 atmospheres can be used within the balloon to apply compressive forces to the vessel without danger of rupturing the vessel. It should be appreciated that the non-elastic capabilities can also be achieved by a composite elastic material.
Since the blood flow has been restored to the vessel 567 by the shunt hereinbefore described, the compression of the occlusion forming the stenosis 569 can be carried out for an extended period of time, as for example after a few minutes, if desired to help ensure that a large lumen or passageway is formed through the stenosis 569 as shown in
After the appropriate dilation the stenosis 569 has been accomplished the third balloon can be removed from the stenosis while aspiration of the working space 576 is still ongoing so that any plaque coming off the occlusion forming the stenosis 569 can be aspirated out of the vessel. After the third balloon 558 has been removed from the stenosis, the second balloon 536 and the first balloon 519 can be deflated to permit normal blood flow through the vessel 567 after which the arterial blood flow supply to the fitting 538 can be terminated. The entire catheter assembly 511 can then be removed from the guiding catheter 563 after which the guiding catheter 563 can be removed and a suture applied to the incision created to obtain access to the femoral artery.
In place of the third balloon 558 for causing compression of the occlusion forming the stenosis 567 to create a larger passageway therethrough, an atherectomy device 581 (see
Means is provided for rotating the second tubular member 586 and consists of suitable means such as a spur gear 601 mounted on the proximal extremity 587 of the tubular member 586. The spur gear 601 is driven in a suitable manner as for example by another smaller spur gear 601 which is of greater width than spur gear 601 so as to provide a splined gear connection between the gears 601 and 602. This accommodates the desired longitudinal movement for the tubular member 586 so that the distal extremity 588 of the tubular member 586 can be advanced and retracted in the working space 576 as hereinbefore described. An electrical drive motor 603 is provided for driving the gear 602.
Atherectomy means 606 is provided on the distal extremity 588 of the flexible elongate tubular member 586. As shown in
When the distal extremity 588 of the flexible elongate tubular member 586 has been introduced into the working space 576, the end or tip 609 of the flexible elongate member 607 of the atherectomy means 606 is free. A saline solution is introduced into the fitting 557. Thereafter the motor 603 can be energized to cause rotation of the tubular member 586 and to thereby cause rotation of the helically wound flexible elongate member 607 to cause its free end or tip 609 to be moved outwardly radially under centrifugal force to bring the cutting edge 612 into engagement with the plaque 569 in the stenosis 569 to cause progressive removal of the plaque forming the stenosis 569 to enlarge the passageway extending through the stenosis. Because of the rounded configuration of the tip 609, the tip 609 will not dig into the vessel wall but will only remove plaque which is engaged by the cutting edge 612. As the plaque is being removed, the saline solution introduced through the fitting 596 into the space 576 picks up the plaque particles or emboli as they are being removed. The saline solution with the plaque or emboli therein is removed through the spiral groove 598 and through the aspiration port 527. The flexible elongate tubular member 586 can be moved back and forth so that the cutting tip 609 engages the length of the stenosis 569 so that substantially all of the stenosis 569 can be removed.
Means is provided to sense when sufficient plaque has been removed from the stenosis 569 and to ensure that cutting edge 612 does not cut into the vessel wall. An ultrasonic sensor 616 (see
As soon as a desired amount of plaque has been removed from the stenosis 569 to provide the desired passage through the stenosis, rotation of the tubular member 586 is terminated after which the tubular member 586 can be withdrawn followed by deflation of the second balloon 536 and withdrawing it. Deflation of the first balloon 516 then occurs after which it is withdrawn from the vessel 567. Thereafter, the guiding catheter 563 can be removed and the incision closed as hereinbefore described.
In order to ensure that restenosis will not take place, it may be desirable to place a cylindrical stent 626 in the stenosis 569. Such a stent 626 can be a self-expanding stent formed of a suitable material such as a superelastic Nitinol and movable between unexpanded and expanded conditions. Such a stent 626 can be placed by a suitable catheter apparatus 631 of the type shown in
After the stent 626 has been discharged out of the end of the first flexible elongate tubular member 516, the stent 626 will self expand toward its expanded condition until it is in engagement with the wall of the vessel in the vicinity of the occlusion forming the stenosis 569 to frictionally retain the stent in engagement with the vessel wall. As soon as the stent 626 is in engagement with the vessel wall, the second balloon 536 can be deflated as can the first balloon 519. The first deflated balloon 536 can then be withdrawn through the interior of the cylindrical stent 626. This can be followed by deflation of the first balloon 519 and the removal of the flexible elongate tubular member 516 with its first balloon 519 and the flexible tubular member 531 with its second balloon 536, along with the flexible elongate member 636 until the entire catheter assembly or apparatus 631 has been removed from the guiding catheter 563. Thereafter the guiding catheter 563 can be removed and the incision sutured as hereinbefore described.
In
As hereinafter explained, the apparatus 651 shown in
The tubular member 677 is also provided with a large lumen 691 having a suitable size as for example 0.045″ which is adapted to slidably receive therein a therapeutic balloon catheter 692 and a perfusion balloon catheter 693. It is also provided with another lumen 696 having a suitable size as for example 0.026″ which is adapted to receive a balloon-on-a-wire catheter 697. It is also provided with an aspiration lumen 701 having a suitable size as for example 0.025″ and an irrigation lumen 702 having a suitable size as for example 0.015″. There is also provided another lumen 703 which can be used for other purposes.
The therapeutic balloon catheter 692 and the perfusion balloon catheter 693 are constructed in a manner similar to the balloon catheters hereinbefore described. Thus the perfusion balloon catheter 693 is provided with a flexible elongate tubular member 706 having proximal and distal extremities 707 and 708. A balloon 709 formed of an elastic material is secured to the distal extremity 708 by suitable means such as an adhesive (not shown) and is adapted to be inflated through a port 710 in communication with a balloon inflation lumen 711. The tubular member 706 is also provided with a blood perfusion lumen 712 which is centrally disposed therein. The proximal extremity 707 of the tubular member 706 is connected to a Y adapter or fitting 713 of which the central arm 714 is in communication with the blood perfusion lumen 712 and is provided with a Luer-type fitting 716. The side arm 717 of the fitting 713 is in communication with the balloon inflation lumen 711 and is provided with a Luer-type fitting 718 adapted to be connected to a source of pressure as hereinafter described.
The therapeutic balloon catheter 692 consists of a tubular member 721 having a proximal and distal extremities 722 and 723. A balloon 724 formed of a non-elastic material is secured to the distal extremity 723 by suitable means such as an adhesive. A port (not shown) is in communication with the interior of the balloon 724 and is in communication with a balloon inflation lumen 726. A Luer-type fitting 727 is mounted on the proximal extremity 722 and is in communication with the balloon inflation lumen 726. Another fitting 728 is mounted on the proximal extremity 722 and is in communication with a large centrally disposed lumen 729 which can receive the perfusion balloon catheter 693 for slidable movement as hereinafter described.
The balloon-on-a-wire catheter 697 is slidably mounted in the lumen 696 and consists of a guide wire 731 of a conventional construction having a suitable diameter as for example 0.018″ and having a proximal and distal extremities 732 and 733. A balloon 734 formed of a non-elastic material is mounted on the distal extremity 733 and is secured thereto by suitable means such as an adhesive (not shown). The proximal extremity of the balloon 734 is secured to the distal extremity of a tubular member 736 formed of a suitable material such as plastic and which is coaxially disposed on the guide wire 731. The tubular member 736 extends the length of the guide wire to the proximal extremity and is connected to a Luer-type wye fitting 737 and is in communication with an annular lumen 738 disposed between the tubular member 736 and the exterior surface of the guide wire 731. The lumen 738 is in communication with the interior of the balloon 734 for inflating and deflating the balloon 734. The balloon-on-a-wire catheter 697 is adapted to be introduced through a fitting 741 carried by a tube 742 mounted in the manifold 686 and in communication with the lumen 696 in the multi-lumen elongate tubular member 677.
A tube 746 is mounted in the manifold 686 and is in communication with the large lumen 691 and is provided with a fitting 747 which is adapted to receive the perfusion balloon catheter 693 and the therapeutic balloon catheter 692 as hereinafter described. Another tube 751 is provided in the manifold 686 and is in communication with the aspiration lumen 701. It is provided with the fitting 752. Another tube fitting 753 is mounted in the manifold 686 and is in communication with the irrigation lumen 702 and is provided with a fitting 754.
The various fittings for the catheter as hereinbefore described are adapted to be connected into a control console 771. The control console 771 consists of a rectangular case 772 which is provided with a front panel 773.
A plurality of balloon inflation deflation devices 776 of a conventional type typically called endoflaters are mounted within the case 772 and have control handles 777 extending through vertically disposed slots 778 provided in the front panel. These endoflaters 776 are labeled as shown in
A three-way valve 816 is associated with each of the endoflaters 776 and has a control knob 817 extending through the front panel 753 and is adaptable to be moved between three positions with a center off position and an aspiration position in a counter-clockwise direction and a pressurized position in a clockwise position as viewed in
Operation and use of the apparatus 651 may now be briefly described as follows. Let it be assumed that it is desired to treat a stenosis occurring in a bifurcation in a carotid artery as depicted by the illustrations shown in
As soon as or during the time this retrograde circulation of blood is established through the roller pump 801, the perfusion balloon catheter 693 extending proximally from the fitting 747 is advanced into the internal carotid 669 past the stenosis 821 at the bifurcation 667. If necessary, a guide wire can be utilized which can be introduced through the perfusion lumen 712 to aide in advancing the perfusion balloon catheter 693 into the internal carotid 669. Any emboli or debris dislodged from the stenosis 621 by crossing the same either by the guide wire or by the distal extremity of the catheter 693 will be picked up by the retrograde flow of blood which is being aspirated through the proximal occlusion balloon catheter 676 to thereby prevent any emboli or debris from entering the brain of the patient. The elastic perfusion balloon 709 is then inflated as shown in
Prior to or after the balloon 709 of perfusion catheter 693 has been inflated, the balloon-on-a-wire catheter 697 extending proximally of the fitting 741 is advanced into the external carotid 669 as shown in
As soon as retrograde flow of blood has been terminated, perfusion of blood is started. This can be accomplished by connecting a cannula (not shown) to the fitting 716 of the perfusion catheter 706 and to obtain a supply of blood from the femoral artery in the other leg of the patient. Alternatively, an outside blood supply can be used. Thus fresh blood will be supplied from the femoral artery of the patient directly into the perfusion balloon so that it is discharged distally of the perfusion balloon 709 as shown by the arrows 828 to continue to supply blood to the carotid artery. It has been found that it is unnecessary to a supply perfusion of blood to the external carotid artery because there is sufficient auxiliary circulation in that carotid artery during the time the procedure is taking place.
In the event there is inadequate pressure on the arterial blood being perfused to overcome the resistance in the lumen 669, the roller pump 801 can be utilized by merely operating the same in a reverse direction and connecting it between the cannula and the perfusion catheter.
After the lesion or stenosis 821 has been bracketed as hereinbefore described and a working space 836 formed adjacent the stenosis or lesion 821, a therapeutic procedure can be employed. By way of example this can consist of advancing the therapeutic balloon catheter 692 over and axially of the perfusion catheter 693 to bring its balloon 724 into registration with the stenosis 821 as shown in
As hereinbefore described with a previous embodiment, in place of the therapeutic balloon catheter, other types of catheters can be utilized as for example one incorporating an atherectomy device of the type hereinbefore described to facilitate removal of the stenosis. It is readily apparent that during these procedures if it is necessary to supply a saline solution or a heparinized solution into the working space that the working space can also be continued to be aspirated to remove any debris or emboli which occur during the procedure.
Let it be assumed that the desired therapeutic actions have been undertaken and that the stenosis 821 has been reduced and substantially eliminated so that there is adequate flow through the internal carotid. If it can be seen that there also is a stenosis in the external carotid, the balloon-on-a-wire catheter 697 and the perfusion catheter 693 can be withdrawn and moved so that they enter the opposite carotid to permit therapeutic treatment of a stenosis occurring in the other carotid.
When all the desired therapeutic procedures have been accomplished, the supply of saline or contrast solution can be terminated and the therapeutic balloon 724 deflated. The balloon 734 of the balloon-on-a-wire catheter can be deflated as well as the perfusion balloon 709. Perfusion of blood through the perfusion catheter can be terminated. The perfusion balloon catheter 693 and the balloon-on-a-wire catheter 697 can be retracted into the main multi-lumen tubular member 677 of the proximal occlusion balloon catheter after which the perfusion balloon catheter can be withdrawn carrying with it the other catheters disposed therein. Thereafter, the guiding catheter can be removed and a suture applied to the incision made to gain access to the femoral artery.
It is readily apparent that similar procedures can be carried out with respect to other vessels in the body, such as saphenous vein grafts in the heart, and particularly with respect to vessels in the brain where it is difficult if not impossible to employ surgical procedures as for example with respect to the basilar arteries in which bifurcations appear.
As also herein before explained, the catheter apparatus of the present invention can be utilized for deploying stents. Where that is desirable the apparatus of the present invention, perfusion can be accomplished during employment of the stent.
From the foregoing it can be seen that an apparatus and method has been provided for treating occluded vessels and particularly for treating carotid arteries. The apparatus and method of the present invention is particularly advantageous for the carotid arteries because it permits access to portions of the carotid arteries which are not accessible by surgery.
The catheter apparatus assembly and method of the present invention are also particularly useful for treating other occluded vessels but particularly the carotid arteries because it makes possible the removal of plaque without endangering the patient. An operating or working space is provided while shunting blood around the working space so that there is continued blood flow in the vessel to support the functions which are normally supported by the vessel. As also pointed out above, the apparatus and method of the present invention are particularly useful in connection with vessels having bifurcations therein and in which the stenosis occurs at or near the bifurcation. From the foregoing it can be seen with the apparatus and method of the present invention, retrograde flow of blood is accomplished during deployment of the device to prevent undesired travel of emboli. Occlusion of the vessels is provided to obtain a working space by bracketing the working space with balloons while at the same time maintaining perfusion of blood making it possible to utilize a substantial period of time for undertaking therapeutic procedures with respect to the bracketed stenosis.
In connection with the present apparatus and method for treating occluded vessels, it has been found that it is possible to utilize the apparatus and method without perfusion and other procedures involving the carotid arteries and saphenous vein grafts for periods of time extending over five minutes and greater which has made it possible to simplify the apparatus and the method utilized in conjunction therewith.
With respect to an apparatus or assembly which does not require the use of perfusion, a main catheter 851 utilized as a part of the apparatus is shown in
If it is desired to provide a flexible elongate member 852 which has a greater flexibility at the distal extremity, a different material can be used in the distal extremity 854. For example, the distalmost 5-15 centimeters can be formed of a material such as PEBAX having a Shore D hardness of 35-50 with the remainder of the flexible elongate member 852 having a Shore D hardness of 65-75.
A supplemental flexible elongate tubular member 861 is provided which has incorporated therein a balloon inflation lumen 862. The supplemental flexible elongate tubular member 861 can be of a suitable size as for example an I.D. of 0.014″ and an O.D. of 0.018″ and formed of a suitable material such as a polyimide. The supplemental flexible elongate tubular member has a length which is almost as long as the flexible elongate tubular member 852 and overlies the outside wall of the flexible elongate tubular member 852 and extends from the proximal extremity to near the distal extremity as shown in
As can be seen from
A main adapter or fitting 886 formed of a suitable material such as plastic is mounted on the proximal extremity 853 of the flexible elongate tubular member 852. It is provided with a first Luer fitting 887 which provides a balloon inflation port 888 in communication with the balloon inflation lumen 862. It is also provided with another Luer fitting 889 which is provided with an aspiration port 891 in communication with the main central lumen 857. The main adapter 886 is also provided with a Tuohy-Borst fitting 892 which is in communication with the central lumen 857. The Tuohy-Borst fitting 892 is adapted to receive therapeutic devices, as for example a balloon-on-a-wire device as hereinafter described and is adapted to form a liquid-tight seal therewith by an o-ring 893.
A balloon-on-a-wire device 901 incorporating the present invention is shown in
It has a suitable length as for example 150 cm. The guide wire 902 is provided with proximal and distal extremities 903 and 904 and is provided with a central lumen 906 extending from the proximal extremity to the distal extremity. The lumen can be of a suitable size as for example 0.010″ I.D. for an 0.014″ O.D. guide wire.
An occlusion balloon 911 is coaxially mounted on the distal extremity 904 of the guide wire 902. The occlusion balloon 911 is preferably formed of the same material as the occlusion balloon 869 on the main catheter 851. The occlusion balloon 911 has proximal and distal extremities 912 and 913. A tube 916 formed of a suitable material such as a polyimide is disposed within the occlusion balloon 911 and has a bore 917 extending therethrough which is sized so that it is slightly larger than the outside diameter of the guide wire 902 so that its proximal extremity can be slipped over the distal extremity 904 of the guide wire 902 and then bonded thereto by suitable means such as an adhesive 918. A plurality of circumferentially spaced apart radially extending inflation holes 919 are provided in the proximal extremity of the tube 916 and are in alignment with similarly spaced holes 921 provided in the distal extremity 904 of the guide wire 902 so that they are in communication with the central lumen 906 of the guide wire 902. The inflation holes 919 as shown are in communication with the interior of the occlusion balloon 911 so that fluid passing from the passage 906 can be utilized for inflating the occlusion balloon 911.
A solid core wire 923 formed of a suitable material such as stainless steel is provided with a proximal tapered extremity 924. The core wire 923 is sized so it is adapted to fit within the lumen 906 of the guide wire 902 and is secured therein by suitable means such as an adhesive 926 or alternatively a weld. The core wire 923 has a tapered portion 923a which commences at the proximal extremity 924 and which is tapered so that the cross-sectional diameter progressively decreases to the distal extremity of the occlusion balloon 911. The core wire 923 is also provided with additional portions 923b and 923c which can be of substantially constant diameter as for example 0.003″. The portion 923 is folded over with respect to the portion 923b so that the portions 923b and 923c lie in a plane to facilitate shaping of the distal extremity of the guide wire 902 during use of the same. The core wire 923 is provided with a distal extremity 927 in which a bend 928 is formed between the two portions 923b and 923c. The bend 928 is secured within a hemispherical solder bump or protrusion 929 which is carried by the distal extremity of a coil 931 formed of a suitable radiopaque material such as platinum or a platinum alloy. The platinum coil 931 can have a suitable outside diameter as for example 0.014″ corresponding to the diameter of the guide wire 902 and can have a suitable length ranging from 1 to 3 cm. The proximal extremity of the coil 931 is secured to the distal extremity of the polyimide tube 916 by suitable means such as an adhesive 932 which can be the same adhesive or a different adhesive 933 utilized for securing the distal extremity 913 of the balloon to the polyimide tube 916 to form a fluid-tight seal between the distal extremity of the occlusion balloon 911 and the distal extremity of the polyimide 916. From this construction it can be seen that the portions 923b and 923c of the core wire 923 in addition to serving as a shaping ribbon are also utilized as a safety ribbon to ensure that the tip 928 and the spring 931 cannot be separated from the guide wire 902. The proximal extremity 912 of the balloon 911 is also secured to the proximal extremity of the polyimide tube 916 and also to the distal extremity 904 of the guide wire 902 to form a fluid-tight seal with respect to the occlusion balloon 911 so that the occlusion balloon 911 can be inflated and deflated through the inflation holes 919 and 921.
Alternative constructions for the distal extremity of the core wire 923 are shown in
A removable inflation fitting 941 or valve attachment 941 is mounted on the proximal extremity of the guide wire 902 and forms a part of the balloon-on-a-wire device 901. The fitting or attachment 941 is formed of a suitable material such as a polycarbonate and is provided with a central bore 942. The attachment or fitting is slid externally over the proximal extremity 903 of the guide wire 902. Means is provided for forming a fluid- tight seal between the proximal extremity 903 of the guide wire 902 and a body 943 of the fitting 941 and consists of an o-ring 946 (see
Means is provided for plugging the bore 906 when the removable attachment or fitting 941 is removed and consists of a plug mandrel 956 formed of a suitable material such as 0.014″ stainless steel solid rod. It is necessary that this rod have a diameter which is greater than the diameter of the lumen 906 and the guide wire 902. The plug mandrel 956 is provided with a progressive portion 956a that tapers down from as, for example from 0.014″ to a suitable diameter as for example 0.008″ to a cylindrical portion 956b.
Means is provided for forming a fluid-tight seal between the plug mandrel 956 which forms a plug mandrel and the body 943 of the attachment or fitting 941 and consists of an o-ring 961 providing suitable sealing means seated within a well 962 provided in the body 943. A thumb screw 963 threadedly engages the body 943 and is provided with a cylindrical protrusion 964 which engages the o-ring and compresses it to form a fluid-tight seal with respect to the plug mandrel 956 by rotation in a clockwise direction of the thumb screw 963. The plug mandrel 956 can be released by a counterclockwise rotation of the thumb screw 963 permitting decompression of the o-ring 961.
An irrigation catheter 966 incorporating the present invention is shown in
Operation of the apparatus shown in
Thereafter the main catheter 851 can be introduced into the femoral artery by use of a large conventional guiding catheter because the main catheter 851 is of a relatively large size, as for example 8 to 9.5 French. In order to eliminate the need for such a large guiding catheter, a smaller conventional guiding catheter 986 of the type shown in
The guiding catheter 986 is conventional and thus will not be described in detail. It consists of a flexible elongate tubular member 987 (see
Assuming that the guiding catheter 986 has been inserted into the main catheter 851 before insertion of the main catheter 851 into the femoral artery, both catheters can be inserted in unison while advancing the distal extremity of the guide catheter 986 so that it precedes the distal extremity of the main catheter 851 and serves to guide the main catheter 851 into the vessel of interest, as for example the vessel 981 having the stenosis 982 therein. The main catheter 851 is then advanced so that its distal extremity is at the proximal side of the stenosis 982. By way of example, the main catheter 851 can be advanced through the aortic arch of the heart and thence into a saphenous vein graft so that the occlusion balloon 869 on its distal extremity is positioned proximal of the stenosis 982. As soon as this has been accomplished, the guiding catheter 986 can be removed.
As soon as the distal extremity of the main catheter 851 has been deployed so that it is just proximal of the stenosis 982 to be treated, an assembly shown in
Let it be assumed that it is now desired to inflate the occlusion balloon 869 carried by the main catheter 851. This can be accomplished in a suitable manner such as with an inflation-deflation device represented schematically by a syringe 1002 secured to the fitting 887 (see
The occlusion balloon 911 can then be readily inflated by use of a syringe 1005 secured to the fitting 951 of the removable valve fitting or attachment 941 of the balloon-on-a-wire device 901 proximal of the fitting 886 and accessible outside the body of the patient. The occlusion balloon 911 is inflated (see
Now let it be assumed that the occlusion balloon 911 has been inflated with the appropriate working space 1003 and that it is desired to introduce a therapeutic balloon catheter 1001 into the working space 1003 to treat the stenosis 982. If the therapeutic catheter 1001 is not in the main catheter 851 as hereinbefore described, this can be readily accomplished in the present invention by inserting a plug mandrel 956 into the open end of the lumen 906 of the guide wire 902. After the plug mandrel 956 has been inserted, the syringe 1005 can be removed after which the thumb screws 948 and 963 can be loosened to permit the o-rings therein to become decompressed and to release the guide wire 902 and the plug mandrel 956 to permit the fitting or valve attachment 941 to be slipped off to provide a proximal end on the guide wire 902 which is free of obstructions. During removal of the valve attachment or fitting 941, the occlusion balloon 911 remains inflated and continues to be disposed distally of the stenosis 982. The occlusion balloon 869 also remains inflated because the syringe 1002 remains attached to the fitting 886 and is disposed proximal of the stenosis 982.
The conventional therapeutic catheter 1001 then can be delivered over the guide wire 902 if it is not already present. The therapeutic catheter 1001 is provided with a flexible elongate tubular member 1006 having proximal and distal extremities 1007 and 1008 with a central flow passage (not shown) extending between the same. A therapeutic balloon 1009 on its distal extremity is adapted to be inflated to therapeutic pressures ranging from 4-20 atmospheres through a balloon inflation lumen (not shown) carried by the flexible elongate tubular member 1006 through an adapter 1011 mounted on the proximal extremity 1007. The therapeutic balloon 1009 can be considered to be means for performing work carried by the distal extremity 1008 of the flexible elongate tubular member 1006. The adapter 1011 can be removable of the type hereinbefore described or alternatively can be permanently attached thereto. Assuming that it is a removable adapter, the removable adapter 1011 is provided with knobs 1012 and 1013 carrying o-rings (not shown) adapted to establish fluid-tight seals with the flexible elongate member 1006 and the plug mandrel 956, respectively. It is also provided with an inflation port 1016 similar to those hereinbefore described which is in communication with the inflation lumen (not shown) provided in the flexible elongate tubular member 1006 for inflating the therapeutic balloon 1009.
After the balloon catheter 1001 has been positioned by the use of radiopaque markers (not shown) conventionally employed in such devices, the therapeutic balloon 1009 is disposed so that it is in general alignment with the stenosis 982 as shown in
Let it be assumed that during the compression of the plaque forming the stenosis 982, additional emboli 1004 are formed as shown in
The bulb 1021 is provided with another one-way check valve 1023 which is connected to a flexible collection bag 1024. The bulb 1021 makes it possible to generate a vacuum corresponding approximately to 3-30″ of mercury. Thus, by compressing the bulb 1021 by hand, it is possible to create suction within the chamber or space 1003 formed in the vessel between the occlusion balloons 869 and 911 each time the bulb 1021 is compressed and released. Alternatively, the aspiration can be accomplished by use of a syringe in place of the bulb 1021 and the collection bag 1024. Saline liquid supplied through the irrigation catheter 966 carrying the emboli 1018 is aspirated through the central lumen 857 of the main catheter 851. The aspirated liquid in each cycle of operation created by pressing the bulb 1021 is delivered to the collection bag 1024. With such a procedure it has been found that it is possible to aspirate emboli as large as 800 μm. Such removal can be assured by observing when clear liquid exits outside the body from the aspiration port 891. A chamber having a length ranging from 3 cm to 15 cm can be totally cleared of emboli within a short period of time ranging from 5 to 30 seconds. Alternatively, irrigation can be accomplished by removing the therapeutic catheter 1001 after deflating the therapeutic balloon 1009. The irrigation catheter can be advanced over the balloon-on-a-wire device 901 until the distal tip is just proximal of the occlusion balloon 911 as shown in
After all of the emboli 1004 have been removed, introduction of saline through the tube 1019 is halted. It should be appreciated that the ports for irrigation and aspiration can be reversed in function if desired. Thereafter, the occlusion balloon 911 is deflated by removing the plug 956 and utilizing a syringe 1005, after which the occlusion balloon 869 is deflated permitting blood flow to be reestablished in the vessel 981. Alternatively, the occlusion balloon 869 can be first deflated and aspiration commenced at that time, permitting emboli trapped distally of the occlusion balloon 869 by blood flowing from the proximal side of the occlusion balloon 869 to be aspirated through the central lumen 857. In order to prevent excessive expansion of the vessel 981 being treated, the pressure of the irrigation liquid is typically maintained under 30 psi. This pressure preferably should be below the occlusion balloon pressure.
If it is desired to deliver a stent to the site of the stenosis formed by the plaque 982, this can be readily accomplished during the same procedure. Typically it is desirable to permit the blood to flow normally for a period of several minutes after which the occlusion balloon 869 can be reinflated by the syringe 1005 and the occlusion balloon 911 can be reinflated by inserting the removable valve attachment 941 if it has been removed of the balloon-on-a-wire device 901 and utilizing the syringe 1003 to reinflate the occlusion balloon 911. The plug mandrel 956 can be inserted to keep the occlusion balloon 911 inflated after which the valve attachment 941 can be removed.
A conventional stent delivery catheter 1026 carrying a stent 1027 on its flexible shaft 1028 is introduced over the balloon-on-a-wire device 901 and delivered to the site of the dilated stenosis 982 (see
Heretofore the apparatus of the present invention has been utilized for performing a procedure on a saphenous vein graft where there are no branches to be dealt with. An apparatus incorporating the present invention also can be useful in connection with vessels in a human being having branches therein, as for example the carotids. For this purpose, a main catheter 1031 (see
One of the balloon-on-a-wire devices can be substantially identical to the balloon-on-a-wire device 901 described. The other balloon-on-a-wire device 1035 as shown in
Operation and use of the apparatus of the present invention in performing a procedure in a carotid artery is shown in the cartoons in
Another balloon-on-a-wire device such as the balloon-on-a-wire device 901 is then introduced through the catheter port 1034 and advanced through the central passage or lumen 857 until it exits from the main catheter 1031 after which it is guided into the internal carotid 1043 past the stenosis 1044 so that the occlusion balloon 911 is distal of the stenosis 1044. The occlusion balloon 911 is then inflated as shown by the dotted lines in
The removable valve attachment 941 can then be removed in the manner hereinbefore described so that the proximal extremity of the guide wire 902 is free of obstructions as shown in
In the event it is desired to deliver a stent into the dilated stenosis 1044, this can be accomplished by reinflating the occlusion balloon 869 and then reinflating the occlusion balloons 911 in both of the branches after which a balloon stent delivery catheter 1026 of the type hereinbefore described can be delivered over the guide wire 902 in the same manner as the therapeutic balloon catheter 966 and delivered into the desired location and then deployed in the dilated stenosis 1044. After the stent 1027 has been deposited and the balloon of the stent delivery catheter 1026 is deflated, the irrigation and aspiration procedures hereinbefore described can be repeated to remove any emboli within the space formed between the occlusion balloons 911 and 869. The stent delivery catheter 1026 can be removed. After a suitable period of irrigation and aspiration, as for example 5 to 30 seconds, the occlusion balloon 911 can be deflated after which the occlusion balloon 869 can be deflated and the balloon-on-a-wire devices 901 and 1035 removed along with the main catheter 852.
From the foregoing it can be seen that there has been provided a new and improved apparatus and a method for utilization of the same which makes it possible to carry out such stenosis opening procedures without the perfusion of blood. Complete stenosis procedures can be carried out in a period of time which is less than six minutes for each complete procedure. Even though blood flow is occluded during this period of time, this period of time is much less than the period of time, as for example 30 minutes, required for a conventional endoatherectomy. Thus, the procedures of the present invention can be carried out without endangering the patient, as for example the brain or the heart of the patient.
The desire to eliminate the use of a large guiding catheter for use with the main catheter 851 was hereinbefore discussed. Also, it was hereinbefore disclosed that the main catheter 851 can be inserted independently through a conventional sheath (not shown) in the femoral artery and thereafter a smaller conventional guiding catheter 986 is introduced through the main catheter so that its distal extremity 989 is in the vessel. In other procedures it may be desirable to carry this concept still further, i.e. eliminating the need for a large guiding catheter and also the need for a smaller guiding catheter to be advanced through the main catheter. To do this, it may be desirable to provide a distal extremity on the main catheter 851 which is shaped in a predetermined manner. For example, in the main catheter 851a shown in
Since the main catheters 851a and 851b are relatively flexible, they can be inserted into the femoral artery and have their distal extremities guided into the desired locations with the catheter being selected for the appropriate bend to reach the desired location. With the main catheter having such capabilities, it is possible in connection with the present invention to advance the main catheter 851 into the desired location by the use of a balloon-on-a-wire device of the type hereinbefore described, or alternatively over a conventional guide wire. This makes it possible to eliminate the use of a guiding catheter and therefore substantially simplify the procedures of the present invention and reduce the costs of such procedures.
In connection with the irrigation catheter 966 hereinbefore described in
In the irrigation catheter 966b shown in
Another embodiment of the balloon-on-a-wire device is shown in
An elongate slot 1111 is ground into the distal extremity of the guide wire 902 to a suitable depth which is in excess of one half of the diameter of the guide wire 902. The slot 1111 is in communication with the lumen 906 and opens into the interior of the balloon 1106. A tapered core wire 1113 is mounted in the distal extremity 904 of the guide wire 902. The core wire 1113 is provided with a portion 1113a which has a progressive decrease in diameter extending from the proximal extremity to a portion 1113b which is generally of a uniform diameter of a suitable size, as for example 0.003″ and is formed into a bend 1116 and extends proximally along the slot 1116 and proximally thereof where it is secured to the guide wire 902 by suitable means such as an adhesive 1118. A coil spring 1121 formed of a suitable material such as stainless steel or platinum extends over the slot 1111 and proximally and distally of the slot 1111 and is secured thereto by suitable means as solder 1122. Positioned in this manner, the coil 1121 generally circumscribes the inner circumference of the balloon 1106 and serves to protect the balloon 1106 from any sharp edges as for example sharp edges formed by the slot 1111 in the coil wire 902. A tip coil 1126 formed of a suitable radiopaque material such as a platinum or a platinum alloy is mounted over the distal extremity of the guide wire 902 and secured thereto by suitable means such as solder 1127. The distal extremity of the tip coil 1126 which may have a suitable length, as for example 3 mm, is bonded to the core wire 1113b by a solder 1128 which encloses the bend 1116 and provides a rounded forwardly protruding surface 1129. The distal extremity 1108 of the balloon 1106 is secured to the coils 1121 and 1126 by an adhesive 1131. Similarly, the proximal extremity 1107 of the balloon 1106 is secured to the guide wire 902 and the portion 1113b by an adhesive 1132.
The balloon-on-a-wire device 1101 can be utilized in the same manner as the balloon-on-a-wire device 901 hereinbefore described. It is believed that the balloon-on-a-wire device 1101 has several desirable features. For example the balloon 1106 is protected from any sharp edges by the coil spring 1121. The slot 1111, in addition to providing a means for inflating the balloon, also serves to provide a progressive weakening of the distal extremity of the guide wire 902 to impart additional flexibility to the distal extremity of the device.
By utilizing a balloon-on-a-wire constructions herein disclosed, it is possible to reduce the overall size of the apparatus for the procedures. In view of the fact that guide wires having a size of 0.014″ to 0.018″ are utilized in the present invention, many conventional therapeutic balloon devices can be utilized by advancing the same over such size guide wires. By the provision of removable valve attachments for the balloon-on-a-wire devices, it is possible to use such devices for providing the one or more balloons necessary for a procedure while at the same time making it possible to utilize such devices as guide wires after removing the removable valve attachments on the proximal extremities. This makes it possible to utilize conventional stent delivery catheters, ultrasound catheters and the like by advancing them over the already in place guide wires.
It should be appreciated that it may be possible to eliminate the use of the occlusion balloons 911 which are distal of the proximal balloon carried by the main catheter and distal of the stenosis, since blood flow is occluded during the time that the occlusion balloon 869 is inflated.
Another embodiment of a catheter apparatus incorporating the present invention for treating occluded vessels is shown in
Self-expanding sealing means 1166 is mounted on the distal extremity 1154. This self-expanding sealing means 1166 can take any suitable form. For example, as shown it can consist of a braided structure 1167 formed of a suitable shape memory material such as a nickel titanium alloy that will attempt to expand to a predetermined shape memory. Other than shape memory materials, other materials such as stainless steel, titanium or other materials can be utilized in the braid 1167 as long as they have the capability of expanding when the self-expanding seal means is released. Also it should be appreciated that the self-expanding seal means 1166 can be comprised of an absorbent material which when it absorbs saline or blood expands to form a seal. Such seals can be readily accomplished because it is only necessary to form a seal of approximately one atmosphere to prevent small particles from moving downstream.
In order to prevent abrasion of a vessel, it is desirable to cover the braided structure 1167 with a covering 1168 of a suitable material such as a polymer which extends over the braided structure 1167 and which moves with the braided structure 1167 as it expands and contracts. The polymer can be of a suitable material such as silicone, C-flex, polyethylene or PET which would form a good sealing engagement with the wall of the artery.
Means is provided for compressing the self-expanding sealing means 1166 so that the apparatus can be inserted into the vessel 981 and consists of an elongate sleeve 1271 having proximal and distal extremities 1272 and 1273 and a bore 1274 extending from the proximal extremity 1272 to the distal extremity 1273. A collar 1276 is mounted on the proximal extremity 1272 of the sleeve 1271 and is positioned near the adapter 1156. The collar 1276 serves as means for retracting the sleeve as shown in
Another embodiment of a catheter apparatus for treating occluded vessels incorporating the present invention is shown in
In accordance with the hereinbefore described descriptions, it is apparent that the apparatus can be readily deployed and serve the same function as the main catheter. To accomplish this, the assembly 1281 can be introduced into the femoral artery and the distal extremity advanced into the desired location in the arterial vessel. After it has been properly positioned, the physician can retract the sleeve 1296 to permit the self-expanding seal means 1291 to expand and to form a seal with the wall of the arterial vessel to occlude the arterial vessel and interrupt the flow of blood in the vessel to provide a working space distal of the occlusion formed. This prevents small particles which may thereafter be dislodged from moving downstream. Since a central lumen is available, the therapeutic procedures hereinbefore described can be employed with the catheter apparatus shown in
Thus it can be seen that it has been possible to substantially reduce the complexity of the apparatus utilized in such procedures. This reduces the cost of the apparatus used therein as well as reducing the time required for performing such procedures making the procedures less costly.
E. Treatment Methods Described in U.S. Pat. No. 6,022,336
Referring to
Although
The operation and use of the emboli containment system utilizing the catheters of the present invention for treating occluded vessels will now be described in connection with an occlusion formed by a stenosis in a carotid artery, as illustrated in FIGS. 61A-H. It should be noted that this application is merely exemplary, and that the method of the present invention can be used in other blood vessels in the body as well. The word “proximal” as used herein refers to the portion of the catheter closest to the end which remains outside the patient's body, while “distal” refers to the portion closest to the end which is inserted into the body.
A guiding catheter (not shown) is first introduced into the patient's vasculature through an incision in the femoral artery in the patient's groin. The guide catheter is advanced through the artery into the aorta of the heart of the patient and into the ostium of the carotid artery to be treated, where it remains throughout the procedure if needed. Fluoroscopy is typically used to guide the catheter and other devices to the desired location within the patient. The devices are typically marked with radiopaque markings to facilitate visualization of the insertion and positioning of the devices.
Referring now to
Alternatively, a guide catheter or angiography catheter can first be delivered to the site of the occlusion. The inner catheter is inserted through the guide or angiography catheter, and positioned within the patient. The guide or angiography catheter is removed, and the main catheter is inserted over the inner catheter into position proximal to the occlusion. The occlusive device at the distal end of the main catheter is activated, the occlusive device on the inner catheter is put into position distal to the occlusion and activated, and the procedure continues as described above.
Alternatively, the main catheter can be delivered directly to a position just proximal to the occlusion, without use of a guide or angiography catheter. The inner catheter is then delivered through the main catheter as described above.
In another alternative embodiment of the present invention, the inner catheter can be delivered first through the guide catheter. The occlusive device on the distal end of the inner catheter is positioned distal to the occlusion. The main catheter is introduced over the inner catheter and advanced into the ostium of the carotid artery and into the lumen of the vessel. The main catheter is advanced until the balloon is just proximal to the occlusion. The intermediate catheter is then delivered into the chamber to provide appropriate therapy. The occlusive devices on the distal ends of the inner and main catheters are activated, to create a treatment and isolation chamber surrounding the occlusion. This method can be used when the physician determines that the risk of crossing the occlusion prior to activation of the proximal occlusive device is minimal.
Referring now to
The term “therapy catheter” is meant to include any of a number of known devices used to treat an occluded vessel. For example, a catheter carrying an inflatable or mechanically activated balloon for use in balloon angioplasty, as is used in this example, can be delivered to dilate the stenosis. Thermal balloon angioplasty includes the use of heat to “mold” the vessel to the size and shape of the angioplasty balloon. Similarly, an intravascular stent can be delivered via a balloon catheter and deployed at the site of the stenosis to keep the vessel open. Cutting, shaving, scraping, or pulverizing devices can be delivered to excise the stenosis in a procedure known as atherectomy. A laser or ultrasound device can also be delivered and used to ablate plaque within the vessel. Various types of rheolitic devices could be used. Various thrombolytic or other types of drugs can be delivered locally in high concentrations to the site of the occlusion. It is also possible to deliver various chemical substances or enzymes via a catheter to the site of the occlusion to dissolve the obstruction. A combined aspiration and therapy catheter can also be used. The term “therapy catheter” encompasses these and other similar devices.
Referring now to
After appropriate therapy has been performed and the occlusion 1506 has been removed or lessened using any of the methods and apparatus described above, the therapy balloon 1526 is deflated as illustrated in
In an alternative embodiment not shown, after therapy has been performed to remove or reduce the occlusion the therapy catheter is removed from the emboli containment system, and an irrigation catheter is delivered to the emboli containment chamber. The irrigation catheter is inserted through the main catheter lumen. The main lumen of the irrigation catheter can ride over the inner catheter, or the inner catheter can be positioned in a separate lumen adjacent to the main lumen. The distal end of the irrigation catheter is positioned just proximal the distal occlusion balloon, preferably approximately 1-2 cm from the balloon. As noted above, the irrigation and main catheter are sized such that the irrigation catheter can pass through the main catheter lumen and the annulus or outer pathway between the main catheter lumen and the irrigation catheter is large enough to allow aspiration of the blood and debris through it. Irrigation fluid is provided through the inner pathway between the inner catheter and the irrigation catheter. Alternatively, an aspiration catheter, a combined irrigation/aspiration catheter, or similar debris removing device such as a rheolitic device, can be used as the intermediate catheter. In this embodiment of the invention, the aspiration catheter is delivered in the same manner as described above for the irrigation catheter. Aspiration then occurs through the inner pathway, while irrigation is provided through the outer pathway.
Once the desired catheters are properly positioned, irrigation and aspiration are performed. The irrigation fluid and aspiration pressure are delivered in such a way as to ensure that the change of pressure within the chamber is below about 50 psi to avoid damaging the vessel. The irrigation fluid, preferably normal saline solution, is preferably delivered at a pressure of from about 5 psi to about 50 psi; 5 psi is preferred. The aspiration pressure is preferably between about −5 and −30 in-Hg, and more preferably is about −20 in-Hg. Again, these pressures are measured from at the proximal end of the catheters. The irrigation and aspiration can be delivered simultaneously, continuously, or delivery can be pulsed, or one can be delivered continuously while the other is delivered in a pulsed fashion. The user can determine the best method of delivery to provide optimized flow, turbulence, and clearance within the chamber.
Referring again to
In another embodiment of the present invention, after the therapy catheter is removed, the aspiration catheter is delivered such that its distal end is positioned approximately 1-2 cm from the distal occlusive device. The proximal occlusive device is then deactivated, to allow blood flow into the chamber. This blood flow is used as irrigation flow. The blood, acting as irrigation fluid, is aspirated together with particles and debris through the aspiration catheter. This eliminates the need for a separate source of irrigation fluid. In this embodiment, it is preferred that the blood flow rate in the vessel is greater than about 100 cc/min, and flow rates of 60-80 cc/min are preferred. This method is illustrated in
In yet another embodiment, illustrated in
Aspiration and irrigation are continued until particles and debris 1524 are removed from the chamber 1522, then the irrigation, aspiration, or the therapy catheter 1520, is removed. First the distal 1502 and then the proximal 1512 occlusion balloons are deflated, and the guidewire 1500 and main catheter 1510 are removed. Finally, the guide catheter is removed, and the incision in the patient's femoral artery is closed.
F. Treatment Methods Described in U.S. application Ser. No. 09/270,150
The preferred embodiments of the present invention provide improved methods for containing and removing emboli resulting from plaque, thrombi or other occlusions. The preferred methods are particularly advantageous for use in the carotid artery and other arteries above the aortic arch. The preferred methods may be used, for example, in the treatment of a stenosis or an occlusion which has a length and a width or thickness resulting in at least partial occlusion of the vessel's lumen. Thus, the preferred methods are effective in treating both partial and substantially complete occlusions of arteries. It is to be understood that “occlusion” as used herein, includes both complete and partial occlusions, stenoses, emboli, thrombi, plaque, and any other substance which at least partially occludes the lumen of the artery. Although the methods disclosed herein are described with specific reference to the carotid arteries, they can be applied to other vessels as well, particularly bifurcated vessels.
As illustrated in
Generally, the preferred methods are adapted for the percutaneous treatment, containment and removal of occlusions within the carotid arteries or other arteries above the aortic arch. In one of these methods, a main catheter having an occlusive device on its distal end is first delivered to the common carotid artery, proximal to the site of the occlusion. It should be noted that, as used herein, “proximal” refers to the portion of the apparatus closest to the end which remains outside the patient's body, and “distal” refers to the portion closest to the end inserted into the patient's body. The occlusive device is activated to stop the downstream flow of blood. Collateral pressures from the Circle of Willis and other vessels keep the blood flow in the direction of the main catheter, preventing any emboli from moving downstream. In another embodiment, a main catheter without an occlusive device on its distal end, or a main catheter having an occlusive device which is not deployed, is delivered to the common carotid artery, proximal to the site of the occlusion.
In either case, an inner catheter having an occlusive device on its distal end is delivered through the main catheter and across the site of the occlusion. Alternatively, a detachable occlusive device can also be used. In either case, the occlusive device is activated at a site distal to the occlusion.
In some cases, a second inner catheter is used to provide a third occlusive device. One inner catheter is delivered to the internal carotid artery, while the other inner catheter is delivered to the external carotid artery. When activated, the three occlusive devices completely isolate the area surrounding the occlusion to be treated.
A therapy catheter is then delivered to the site of the occlusion to treat the occlusion. Such treatment includes, but is not limited to, balloon angioplasty, thermal balloon angioplasty, delivery of an intravascular stent, atherectomy, or radiation treatment.
In one embodiment of the present invention, once therapy is complete, an irrigation catheter is delivered into the working area to provide irrigation fluid. Alternatively, anatomical irrigation can be used, as explained below. Aspiration of the area surrounding the treated occlusion is begun using either the main catheter or a separate aspiration catheter. Blood flow is allowed into the working area to be aspirated by deactivating the occlusive devices on the main and/or inner catheters. This helps to irrigate the area and ensure the removal of particles and debris from the artery.
In another embodiment of the present invention, the need for a separate irrigation catheter and irrigation fluid are eliminated. In the context of removing plaque, thrombi or other blockages from blood vessels, separate irrigation fluid is generally provided through an irrigation catheter to the site of treatment. It has been discovered that the patient's own blood can be used as irrigation fluid, without the need for delivery of a separate irrigation catheter and irrigation fluid.
Although the patient's own flow of blood can provide an irrigation source, situations sometime arise where providing separate irrigation fluid is desired. In such cases a separate catheter is introduced into the patient after the therapy catheter is removed and is delivered within close proximity to the occlusive device. Once the catheter is delivered proximal to the occlusive device, the area is first aspirated through the catheter. By delivering the catheter close to the occlusive device a turbulence is created freeing debris from the edge of the occlusive device and other areas where it may be trapped. The debris is then aspirated from the patient. Following aspiration, irrigation fluid is provided if desired to flush any remaining particles and debris from the internal carotid.
Main Catheter
In the preferred methods, a main or guide catheter is first introduced into the patient's vasculature. This catheter is used to guide the insertion of other catheters and devices to the desired site. A guide catheter (e.g., 9 F) or a long sheath (e.g., 7 F) may be used as the main catheter. If the guide catheter is not sufficiently stiff, then an angiography catheter may be positioned inside the guide catheter, and both the guide catheter and the angiography catheter can be delivered on a guidewire. (The term guidewire is used broadly herein to include elongate members (such as hollow or tubular members) made of metal as well as other materials, such as plastic.) Once the guide catheter is properly positioned, the angiography catheter can be removed. In some embodiments of the present invention, the main catheter has an occlusive device on its distal end. The occlusive device can be an inflatable balloon, filter, expandable braid or other mechanical occlusive device. The occlusive device should be capable of preventing the migration of particles and debris from the working area, either through total or partial occlusion of the vessel. Note that the occlusion of the vessel need not be complete, and that substantial occlusion of the vessel may be sufficient. The catheter should be sized so as to slidably receive the inner, therapy and intermediate (irrigation and/or aspiration) catheters inserted therethrough.
A control manifold 1719 is provided at the proximal end 1712 of the catheter 1710. The control manifold 1719 is generally provided with a number of ports to provide access to the catheter lumen 1730. For example, for the embodiment depicted in
The manifold 1719 is preferably formed out of hard polymers or metals, which possess the requisite structural integrity to provide a functional access port to the catheter lumen, such as for balloon inflation or delivery of irrigation fluid and/or aspiration pressure. In one preferred embodiment, the manifold 1719 is integrally formed out of polycarbonate. Of course, any suitable material may be used to form the manifold 1719, including acrylonitrile butadiene styrene (ABS).
As illustrated in
Alternatively, as illustrated in
Inner Catheter
An inner catheter or guidewire having an occlusive device on its distal end is preferably made of metals such as stainless steel or nitinol, or plastics or composites. The preferred methods can be effectively carried out using any of a number of guidewires or catheters that perform the function of occluding the vessel and allowing for the slidable insertion of various other catheters and devices. The term “catheter” as used herein is therefore intended to include both guidewires and catheters with these desired characteristics.
A preferred inner catheter is illustrated in
The body member 1914 of the catheter apparatus 1910 is in the form of hypotubing and is provided with proximal and distal ends 1914A and 1914B as well as an inner lumen 1915 extending along the tubular member 1914. The balloon member 1916 is coaxially mounted on the distal end 1914B of the tubular member 1914 by suitable adhesives 1919 at a proximal end 1916A and a distal end 1916B of the balloon member 1916 as in the manner shown in
Preferably, the proximal end 1920A of the flexible wire 1920 has a transverse cross sectional area substantially less than the smallest transverse cross-sectional area of the inner lumen 1915 of the tubular member 1914. In the preferred embodiment, the flexible wire 1920 tapers in the distal end 1920B to smaller diameters to provide greater flexibility to the flexible wire 1920. However, the flexible wire may be in the form of a solid rod or a ribbon or combinations thereof.
As shown in
The balloon member 1916 is preferably a compliant balloon formed of a suitable elastic material such as a latex or the like, but can be made of non-compliant materials as well. The flexible coil 1922 is preferably formed of a wire of platinum based alloys or gold. The flexible core-wire 1920 and the tubular member 1914 are preferably formed of a nickel-titanium alloy or stainless steel.
Once the inner catheter has been properly positioned inside the carotid artery at a point distal to the occlusion, the occlusive device at the distal end of the inner catheter is actuated to occlude the vessel distal to the existing occlusion to create a working area. When a detachable occlusive device is used, the occlusive device is positioned at a point distal to the occlusion to be treated, and activated to occlude the artery. It is to be understood that the stenosis or occlusion could be in a discrete location or diffused within the artery. Therefore, although placement of the occlusive device is said to be distal to the stenosis or occlusion to be treated, portions of the diffused stenosis or occlusion may remain distal to the occlusive device.
Therapy Catheter
After the area surrounding the occlusion has been isolated, a therapy catheter then is delivered to the site of the occlusion. The term “therapy catheter” is meant to include any of a number of known devices used to treat an occluded vessel. For example, a catheter carrying an inflatable balloon for use in balloon angioplasty can be delivered to dilate the occlusion. Thermal balloon angioplasty includes the use of heat to “mold” the vessel to the size and shape of the angioplasty balloon. Similarly, an intravascular stent can be delivered via a balloon catheter and deployed at the site of the occlusion to keep the vessel open. Cutting, shaving, scraping or pulverizing devices can be delivered to excise the occlusion in a procedure known as atherectomy. A laser or ultrasound device can also be delivered and used to ablate plaque in the vessel. Thrombectomy devices can be used, as can rheolitic devices, and devices which create a venturi effect within the artery. Various thrombolytic or other types of drugs can be delivered locally in high concentrations to the site of the occlusion. It is also possible to deliver various chemical substances or enzymes via a catheter to the site of the stenosis to dissolve the obstruction. The term “therapy catheter” encompasses these and similar devices.
Aspiration and Irrigation Catheters
After the therapy has been performed and the occlusion has been treated, the working area may be aspirated to remove fluid and debris. Aspiration can be provided through the main catheter if desired. A source of negative pressure is attached at the proximal end of the main catheter, and fluid and debris are aspirated through the main catheter's main lumen. Alternatively, an aspiration catheter or similar debris removing device can be delivered to the working area to remove particles and any other debris. The term “aspiration catheter” includes any device which creates an area of fluid turbulence and uses negative pressure to aspirate fluid and debris, and includes thrombectomy catheters, rheolitic devices and those devices which create a venturi effect within the vessel. Thus, it is possible that a single catheter is used as both the therapy catheter and the aspiration catheter.
An aspiration catheter particularly suited for use with the preferred methods is illustrated in
The aspiration catheter illustrated in
Alternatively, the aspiration catheter 1880 can be of a single operator design, as illustrated in
Although the guidewire lumen 1886 is shown in
In another embodiment not shown, the aspiration catheter can be configured such that the therapy catheter can be inserted through the lumen of the aspiration catheter. The lumen is made large enough to accommodate the desired therapy catheter. This allows the aspiration catheter and the therapy catheter to be delivered into the patient at the same time. When therapy is complete, the therapy catheter is removed while the aspiration catheter remains in place. This eliminates the need to separately deliver the aspiration catheter after removal of the therapy catheter, saving valuable time.
In yet another embodiment, also not shown, the therapy catheter can be built over the aspiration catheter. For example, a dual or triple lumen catheter having a dilatation balloon at its distal end can be used. One lumen is used to inflate the dilatation balloon to be used for angioplasty, while the second lumen is used for aspiration. The third lumen is used as a guidewire lumen. Alternatively, the aspiration catheter can be designed to deploy a stent within the occluded artery, or could include an atherectomy device on its distal end. These designs allows a single combined aspiration catheter and therapy catheter to be delivered into the patient. When therapy is complete, aspiration is carried out without the need to first remove the therapy catheter or separately deliver an aspiration catheter.
Although the inner catheter lumen 1840 is shown in
In another embodiment, not shown, the irrigation and aspiration are conducted through a multi lumen catheter. In this embodiment, a single catheter is used. The catheter includes at least two separate lumens; one lumen is used for aspiration and has a source of negative pressure attached at the proximal end, while a second lumen is used to provide irrigation and has a source of irrigation fluid attached at the proximal end.
Preferred Methods
A. Dual Balloon System
A main catheter or guide catheter 2006 is introduced into the patient's vasculature through an incision in the femoral artery in the groin of the patient, or through direct access to the arteries in the neck (e.g., jugular access, in which case the catheters do not need to be as long as in the case of femoral access). The main catheter 2006 has a lumen sized to receive other catheters and devices, and can be used to guide the insertion of these other catheters and devices. The main catheter 2006 is guided through the vasculature until it reaches the common carotid artery 2004, where it can remain in place throughout the procedure. Fluoroscopy is typically used to guide the main catheter 2006 and other devices to the desired location within the patient. The devices are frequently marked with radiopaque markings to facilitate visualization of the insertion and positioning of the devices within the patient's vasculature.
Once the main catheter 2006 is in place, with its occlusive device 2008 at a position proximal to the occlusion 2010, the occlusive device 408 is activated. Downstream blood flow is effectively stopped, and blood flow coming from collateral blood vessels distal to the occlusive device prevents the downstream migration of any free particles. In this example, the occlusive device 2008 is an inflatable balloon. The balloon is inflated to occlude the common carotid artery 2004.
Next, an inner catheter or guidewire 2020 having an occlusive device 2022 at its distal end is delivered through the main catheter 2006 into the internal carotid artery 2000 and past the site of the occlusion 2010. Alternatively, a detachable occlusive device can be deployed at the site distal to the occlusion, and the delivery device removed. In this example, the occlusive device 2022 is also an inflatable balloon. The balloon is inflated to occlude the internal carotid artery at a site distal to the occlusion 2010. It should be understood that the occlusion within the artery can be in a discrete location or diffused within the vessel. Therefore, although placement of the distal occlusive device is said to be distal to the occlusion to be treated, portions of the diffuse occlusion may remain distal to the occlusive device.
A working area is therefore created between the two occlusive devices 2008, 2022 surrounding the occlusion 2010. A therapy catheter (not shown) is then delivered. The therapy catheter can be any of a number of devices, including a balloon catheter used to perform angioplasty, a catheter which delivers a stent, a catheter for delivering enzymes, chemicals, or drugs to dissolve and treat the occlusion, an atherectomy device, a thrombectomy device, a rheolitic device, a device which creates a venturi effect within the artery, or a laser or ultrasound device used to ablate the occlusion.
Once the desired therapy is performed, the therapy catheter is withdrawn from the patient's body and an aspiration catheter 2024 is delivered through the main catheter 2006, preferably over the inner catheter or guidewire 2020. The aspiration catheter 2024 rides over the guidewire 2020 with the guidewire 2020 inserted through the aspiration lumen of the catheter 2024. Alternatively, a single operator type aspiration catheter can be used, in which only a portion of the aspiration catheter rides over the guidewire, which is inserted into a separate guidewire lumen.
After the aspiration catheter 2024 is in place, aspiration is begun. A source of negative pressure is connected to the aspiration catheter 2024 at its proximal end. A preferred source of negative pressure is any container containing a fixed vacuum, such as a syringe, attached to the proximal end of the aspiration catheter 2024 at the aspiration port. A mechanical pump or bulb or any other appropriate source of negative pressure can also be used, including the creation of a venturi effect within the blood vessel. The difference between the existing pressure within the vessel and the aspiration or negative pressure within the vessel should not exceed about 50 psi. If too much aspiration is applied, the change in pressure in the vessel will be too great and damage may occur to the vessel itself.
Prior to aspiration, simultaneous with aspiration, or after aspiration is begun, the proximal occlusive device 2008 is deactivated to allow blood flow into the area The blood flow into the area provides irrigation fluid which creates turbulence and facilitates the removal of particles and debris. Preferably, the anatomical irrigation pressure provided is approximately 1-1.5 psi, and the blood flow into the area is at least 10 cubic centimeters/min and more preferably about 60-80 cubic centimeters/min. In a preferred embodiment, the proximal occlusive device is then reactivated, and the distal occlusive device is deactivated. This allows blood flow into the working area from the distal end. Following aspiration, the distal occlusive device is reactivated. This method of alternately deactivating and reactivating the occlusive devices acts to contain and direct the emboli to an area within the working area where they will be aspirated. Particles are initially contained between the two occlusive devices. When the proximal occlusion device is deactivated, blood flow forces particles and debris toward the distal end of the working area. The working area is aspirated, and the occlusive device reactivated. When the distal occlusive device is deactivated, blood flow forces particles and debris back toward the proximal end of the working area, where they are then aspirated. The steps of deactivating and reactivating the occlusive devices and aspirating the working area can be repeated as often as desired, until the working area is substantially free of particles and debris.
When the deactivating and reactivating of the occlusive devices and aspiration steps are complete, the aspiration catheter is removed, and the occlusive devices are deactivated. The main and inner catheters are also removed from the patient.
As described above, the aspiration catheter can be sized such that it can receive the therapy catheter within its lumen. In this case, the aspiration catheter and the therapy catheter are delivered into the artery together. When therapy is complete, the therapy catheter is removed while the aspiration catheter remains in place. When aspiration is complete, the aspiration catheter, inner catheter and main catheter are removed from the patient's body. Delivering the aspiration catheter and therapy catheter together saves time, which is critical during these types of procedures.
In yet another embodiment, aspiration takes place through the lumen of the inner catheter or guidewire. The occlusive device on the inner catheter is positioned distal to the occlusion, and the occlusive device is activated to at least partially occlude the vessel. The therapy catheter is delivered and therapy performed. A source of negative pressure is provided at the proximal end of the inner catheter, and aspiration occurs through openings located at the distal end of the catheter just proximal to the occlusive device. This eliminates the need for a separate aspiration catheter, and the need to remove the therapy catheter prior to aspiration. Again, this saves time, which is critical during these types of procedures.
B. Triple Balloon System
In another embodiment illustrated in
Should it be desired that a separate irrigation catheter be used to provide irrigation fluid, an irrigation catheter can be delivered to the site of the occlusion following therapy and removal of the therapy catheter. The irrigation catheter is delivered through the main catheter and over the inner catheter. Irrigation fluid is provided through the irrigation catheter, while aspiration is provided through the main catheter.
C. Single Balloon System
In another embodiment illustrated in
Once the main catheter 2006 is in place proximal to the occlusion 2010, an inner catheter or guidewire 2020 having an occlusive device 2022 at its distal end is delivered through the main catheter 2006 into the internal carotid artery 2000 and past the site of the occlusion 2010. Alternatively, a detachable occlusive device can be deployed at the site distal to the occlusion, and the delivery device removed. In this example, the occlusive device 2022 is an inflatable balloon. The balloon is inflated to occlude the internal carotid artery 2000 at a site distal to the occlusion 2010. As noted before, it should be understood that the occlusion within the artery can be in a discrete location or diffused within the vessel. Therefore, although placement of the distal occlusive device is said to be distal to the occlusion to be treated, portions of the diffuse occlusion may remain distal to the occlusive device.
A therapy catheter, not shown, is then delivered. Again, the therapy catheter can be any of a number of devices, including a balloon catheter used to perform angioplasty, a catheter which delivers a stent, a catheter for delivering enzymes, radiation, chemicals, or drugs to dissolve and treat the occlusion, an atherectomy device, a thrombectomy device, a rheolitic device, a device which creates a venturi effect within the artery, or a laser or ultrasound device used to ablate the occlusion.
Once the desired therapy is performed, the therapy catheter is withdrawn from the patient's body and an intermediate catheter 2026 is delivered through the main catheter 2006. A single operator type catheter may be used in which only a portion of the catheter rides over the guidewire, which is inserted into a separate guidewire lumen (as illustrated in
Delivery of the intermediate catheter 2026 near the occlusive device 2022 requires passing the intermediate catheter 2026 across the previously occluded vessel. In order to minimize the risk to the patient the intermediate catheter 2026 is preferably soft, small and flexible. A preferred embodiment of this invention comprises delivering a soft-tipped intermediate catheter 2026 made of a compound of a durometer 55 or less.
Once the intermediate catheter 2026 is delivered in close proximity to the occlusive device 2022, the area is first aspirated. As noted above, the intermediate catheter 2026 can be moved backward in a proximal direction during aspiration. This forward and backward movement of the intermediate catheter 2026 can be repeated as often as desired to provide effective aspiration. At some point during aspiration, the distal end of the aspiration catheter should be positioned about 2 cm or less from the proximal end of the occlusive device to ensure effective aspiration. Following aspiration, the area is irrigated by supplying a fluid, such as saline, through the intermediate catheter 2026. The irrigation fluid acts to flush any remaining particles or debris from the internal carotid 2000, to the external carotid 2002, as indicated by the arrows in
In one embodiment, the intermediate catheter 2026 has a single lumen for delivery of aspiration pressure and irrigation fluid, such as the aspiration or irrigation catheters shown in
Following aspiration of the area, the proximal end of the intermediate catheter 2026 is connected to a source of irrigation fluid, such as saline, in order to irrigate the area near the occlusive device 2022. Preferably, the volume of fluid used to irrigate the area near the occlusive device 2022 is equal to or greater than the volume of the area between the proximal end of the distal occlusive device and the start of the internal carotid artery at the bifurcation of the common carotid artery. For example, at least 10 cubic centimeters of fluid is delivered to the area that is between the distal occlusive device and the start of the internal carotid branch, which is approximately 1-5 cubic centimeters. As a result of this irrigation, any particles or debris remaining in the internal carotid 2000 will be flushed into the external carotid 2002.
In yet another embodiment, the intermediate catheter 2026 has two lumens, one for aspiration and another for irrigation. The lumen providing aspiration is attached at its proximal end to a negative pressure source. A second lumen is attached at its proximal end to source of irrigation fluid. An advantage of this embodiment is that the particles and debris removed are in a separate lumen, eliminating the possibility that they could be flushed back into the vessel when the irrigation fluid is delivered through the same lumen as the aspiration pressure. As with the single lumen embodiment, the steps of aspirating and irrigating can be repeated as many times as necessary. Once the emboli have been flushed away, the distal occlusive device may be deactivated and removed from the patient.
As illustrated in
Flushing of the region in and around the treated occlusion 2010′ may be accomplished in a number of ways. For example, as illustrated in
The steps illustrated by
The main (outer) catheter 2006 itself may be used for aspiration and irrigation of the region in and around the treated occlusion 2010′, as illustrated in
Other combinations of the methods illustrated by
Aspiration and irrigation may be performed simultaneously by having two catheters deployed at the same time and irrigating through one (e.g., the therapy catheter 2048 or the intermediate catheter 2026) and aspirating through another (e.g., the main catheter 2006). In this case, the main catheter 2006 may be deployed to a location near the intersection of the internal carotid 2000 and the external carotid 2002. Alternatively, aspiration may be performed through the intermediate catheter 2026 while irrigating through the main catheter 2006, in which the distal ends of the intermediate catheter 2026 and the main catheter 2006 are preferably positioned distal and proximal, respectively, to the treated lesion 2010′.
As shown in
Another irrigation device and method is disclosed in
Instead of pumping irrigation fluid through the holes 2060 as shown in
Irrigation rates for the methods disclosed herein are preferably between 0.1 cc/sec and 3 cc/sec, more preferably between 0.5 and 1.5 cc/sec, and still more preferably about 1 cc/sec. Aspiration rates are preferably between 0.5 and 5 cc/sec, and more preferably between 0.5 and 1.1 cc/sec. The fluid pressure used to generate the irrigation and aspiration rates may be pulsed on and off to better flush away emboli. For example, fluid pressure may be alternately applied for 5 seconds (in the form a pulse) and then turned off for 2-3 seconds. In general, fluid is irrigated (or aspirated) through a lumen in a catheter, with the lumen being in fluid communication with a fluid flow opening at a distal end portion of the catheter.
The single balloon methods disclosed herein may additionally comprise inflating a balloon on the main catheter 2006 within the common portion of the vessel to occlude the common portion.
D. Alternate Dual Balloon System
Under certain circumstances, use of a second occlusive device is desired, as illustrated in
Once the main catheter 2006 is delivered to the common carotid artery 2004, the occlusive device 2032 is activated. The activation of the occlusive device 2032 will have the effect of occluding the common carotid artery 2004 thereby cutting off the blood flow to both the internal carotid 2000 and the external carotid 2002 arteries.
Next, an inner catheter 2020 with an occlusive device 2022 is delivered distal to the occlusion 2010 in the internal carotid artery 2000 and activated, thus isolating the occlusion 2010 between the two occlusive devices 2032, 2022. This is followed by therapy on the occlusion 2010 as described above. Sequential aspiration and irrigation are then performed as described above.
The main advantage of using two occlusive devices is that when the internal carotid artery 2000 is irrigated, a back pressure is created in the chamber defined by the proximal occlusive device 2032 and the distal occlusive device 2022. This back pressure will force the fluid, particles and debris from the internal 2000 and common 2004 carotid arteries through the external carotid artery 2002.
E. Alternate Triple Balloon System
In some cases, a triple balloon system is used. This system is especially advantageous in those patients where occlusion of the common carotid artery results in blood from collateral vessels flowing from the external carotid artery to the internal carotid artery. The direction of blood flow in a particular patient can be determined through angiography.
In this system (not shown), following activation of the occlusive device in the common carotid artery, but before crossing the occlusion with an inner catheter, a first inner catheter with an occlusive device is delivered to the external carotid artery and the occlusive device activated. This prevents flow from collateral blood vessels moving from the external to the internal carotid artery. Next, a second inner catheter is delivered to the internal carotid artery past the site of the occlusion and the occlusive device activated to occlude the internal carotid artery. Alternatively, the first inner catheter can be positioned within the internal carotid artery and the occlusive device activated, followed by delivery of the second inner catheter to the external carotid artery and activation of the occlusive device. In either case, the occlusion is completely isolated between the three occlusive devices. This is followed by therapy on the occlusion, aspiration, and irrigation if desired, as described above.
F. Use of Occlusive Devices in Combination with Perfusion
For some applications, it may be desirable to provide for the perfusion of blood while medical procedures are performed on a blood vessel such as the internal carotid artery. Several such embodiments are now discussed in connection with
After the expandable member 2070 is deployed, therapy may be performed on the lesion 2010, resulting in a treated lesion 2010′. To this end, a therapy catheter (not shown in
Following removal of the therapy catheter, an intermediate catheter 2074, to which an occlusive device 2078 (such as an occlusion balloon) is attached, is directed through the common carotid 2004 (by passing the catheter 2074 over the guidewire 2020 and through a guide or main catheter 2006) and positioned such that the occlusive device 2078 is distal to the treated lesion 2010′ and proximal to (and preferably adjacent proximal to) the expandable member 2070. The occlusive device 2078 may then be deployed to occlude the internal carotid artery 2000, thereby preventing anatomical blood flow. Emboli that have been entrained within the expandable member 2070 may then be advantageously aspirated away by applying suction through the intermediate catheter 2074, such that blood distal to the expandable member 2070 passes through the expandable member, entraining emboli in the process. The aspirated emboli and blood pass through the intermediate catheter 2074 and are directed out of the patient. If the expandable member 2070 is clogged, aspiration will nevertheless draw emboli from the expandable member by drawing blood from the proximal side of the expandable member.
To remove any emboli that may be remaining in and around the treated lesion 2010′, the main catheter 2006 may be brought distal to the treated lesion, as illustrated in
Another embodiment in which an occlusive device is combined with perfusion is illustrated in
Yet another embodiment in which an occlusive device is combined with perfusion is illustrated in
After positioning the (uninflated) occlusion balloon 2114 distal of the lesion 2010 and positioning an opening 2118 of the hypotube 2102 distal of the occlusion balloon 2114, the occlusion balloon is inflated so that the occlusion balloon occludes the vessel 2000 while contacting the hypotube 2102. (The holes 2106 in the hypotube 2102 are preferably located at least 1-2 mm proximal of the lesion to reduce the risk of emboli entering the holes and traveling distal of the occlusion balloon 2114.) Therapy is then performed on the lesion 2010, while the inflated balloon 2114 blocks emboli (produced as a result of the therapy) from traveling downstream. However, blood may still pass through the holes 2106 in the hypotube 2102 and exit the opening 2118 in the hypotube, so that perfusion of blood is allowed. After the therapy is complete and the therapy catheter is removed, a fluid port of the catheter 2110 may be advantageously positioned distal to the treated occlusion 2010′ (and proximal to the balloon 2114) and irrigation fluid delivered distal to the treated lesion 2010′, so that fluid flows across the treated occlusion in a distal to proximal direction. The irrigation fluid carries away emboli towards the junction of the internal carotid 2000 and the external carotid 2002, whereupon the emboli are flushed down the external carotid by anatomical blood flow. As an alternative (not shown) to using a hypotube dedicated for perfusion, holes may be introduced into the guidewire, with the guidewire having a lumen that extends through the occlusion balloon leading to an opening distal of the balloon. The holes 2106 in the hypotube 2102 or in the guidewire 2020 may advantageously have diameters of 0.005″ or larger, or slits of dimensions 0.005″.times.0.005″. Several such hole (or slits) are preferably used to create a flow of blood of between 8 and 50 cc/min.
The perfusion illustrated in
Another embodiment that combines features of occlusion with perfusion is illustrated in
G. Accommodating Changes in Vessel Diameter
As a result of therapy being performed on a lesion, the diameter of the vessel or vessels being occluded may increase. For example, if the internal carotid artery is occluded distal to a lesion within the carotid artery, and then treatment is performed on that lesion, the diameter of the internal carotid artery may increase substantially as a result of the treatment. If the occlusive device in the internal carotid does not accommodate this increase in diameter, resulting in a break in the seal between the occlusive device and the walls of the internal carotid, the risks to the patient may be significant.
A method for avoiding this possibility involves applying an expansion force to the occlusive device beyond that which is required to seal the occlusive device to the walls of the vessel. For example, if an occlusion balloon is used as the occlusive device in the internal carotid, then the balloon may be advantageously inflated to a pressure beyond that which is required to maintain a seal in the internal carotid. As the balloon begins to be inflated, it will expand both axially and radially. The balloon continues to expand radially until it mates with the walls of the vessel, at which point further expansion of the balloon in the radial direction is hindered by the tendency of the vessel to resist enlargement. Continuing to inflate the balloon at this point results in the balloon expanding preferentially in the axial direction, rather than in the radial direction. As the balloon expands in the axial direction, potential energy continues to be stored up in the balloon.
If the vessel expands (e.g., as a result of therapy being performed on it), then the potential energy stored in the balloon is harnessed in that the balloon expands in the radial direction (while correspondingly contracting somewhat in the axial direction), such that the balloon continues to make contact with the vessel during and following treatment, thereby preventing a break in the seal which could result in injury to the patient. Thus, with such a method, it is not necessary to actively adjust the pressure in the balloon as a result of treatment of a lesion, and in this sense, the seal is self-accommodating with respect to changes in vessel diameter.
The occlusive device may also comprise a self-expanding material such as nitinol, for which it is possible to obtain a nearly constant level of stress over a relatively wide range of strain. For example, if an occlusive device comprising a nitinol filter-like mesh is capable of sealing a 6 mm diameter vessel, such an occlusive device may be used to occlude a vessel that is initially 5 mm in diameter, so that if the vessel expands, the perfusion-filter will also expand to maintain occlusion within the vessel.
The diameter of the internal carotid artery may increase substantially as a result of therapy performed on it. For example, a vessel that has a 4 mm diameter at the point where the occlusion balloon is located may increase to 5 mm or more as a result of therapy. Thus, in this method, the balloon may be advantageously positioned in a blood vessel such that the vessel diameter is at least 20% less than the maximum useful sealing diameter of the balloon. As the lesion is treated, the balloon will continue to seal against the walls of the vessel, even if the diameter of the vessel should expand in response to the treatment. This method can be used with a variety of expandable members other than balloons, such as braids, coils, ribs, ribbon-like structures, slotted tubes, and filter-like meshes, which may be partially or completely covered with a membrane or another covering to provide a seal with the vessel.
H. Inflation Apparatus
A preferred embodiment of a low volume or inflation syringe 60 in a syringe assembly 100 for inflating an occlusion balloon in accordance with the present invention is shown in
The sealing member 2530, described in more detail below in connection with
If the balloon 1666 is mounted on the distal end of the catheter 1662, the syringe 1660 and/or syringe assembly 1700 is preferably connected at the proximal end of the catheter 1662. Prior to use of the syringe 1660 to inflate the balloon 1666 to the proper size for the vascular segment to be treated, the distal end of the catheter 1662 and the balloon 1666 are first “primed” or evacuated. The reservoir syringe 1664 of the assembly 1700 may be used for the evacuation. Access to the vascular site is through a port in the patient obtained, for example, using an introducer (not shown). A preferred system and method for accomplishing the occlusion balloon inflation is described below.
The inflation syringe 1660 may be provided with a stop mechanism 1620 for limiting both the intake of fluid into the syringe and the delivery of fluid from the syringe. The syringe 1660 has an elongate cylinder 1644 and plunger arrangement 1650 which provide for greater displacement or travel by the plunger along the cylinder length than is necessary to expel a relatively small amount of inflation fluid. Thus, with the stop mechanism 1620, the clinician is provided with an enhanced sense of whether the fluid in the syringe 1660 has been delivered to the balloon, which helps compensate for lack of precision by the clinician. The stop mechanism 1620 may be mounted on the syringe 1660 during production, or as separate components that can be retro-fit onto an existing supply of syringes.
Referring to
The catheter 1662 (depicted in
The sealing member 2530 is inserted into lumen 2540 through central lumen opening 2523. Sealing member 2530 has a first region 2535 which has an outer diameter substantially the same as the outer diameter of the proximal end 2512 of the catheter tubular body. Region 2535 has a taper 2534, reducing in diameter to a second region 2533 which has an outer diameter less than the inner diameter of lumen 2540. In one embodiment, region 2533 tapers over length 2531 to form a plug mandrel wire 2532. As a consequence, region 2533 and plug mandrel wire 2532 are slidably insertable into the proximal opening 2523 of catheter 1662 and may move within lumen 2540. In one preferred embodiment, region 2535 has an outer diameter of about 0.013 inches, region 2533 has an outer diameter of about 0.008 inches, and plug mandrel wire 2532 has a diameter of about 0.006 inches, with region 2533 and plug mandrel wire 2532 being inserted into a catheter having a central lumen 2540 with an inner diameter of about 0.009 inches.
The length of sealing member region 2535 extending proximally of catheter 1662 may vary in length depending upon the intended use environment. For example, where catheter 1662 is to be used as a guide for other catheters in an “over-the-wire” embodiment, it is preferred that the total length of catheter 1662 and sealing member region 2535 be about 300 centimeters. Alternately, where catheter 1662 is to be used in a single operator or rapid exchange embodiment, it is preferred that the total length of catheter 1662 and region 2535 be about 190 centimeters. Accordingly, with a known catheter length and use environment, an appropriate length for region 2535 may be chosen.
Regions 2535 and 2533 and plug mandrel wire 2532 may all be made out of metals such as stainless steel. Alternatively, combinations of materials may be used as well. For example, in some applications it may be desirable to manufacture regions 2535 and 2533 out of stainless steel, while manufacturing plug mandrel wire 2532 out of nitinol. Furthermore, the various sealing member regions may be made from a single metal wire strand coined at various points to achieve the desired dimensional tolerances, or multiple segments may be joined together to form sealing member 2530.
Where multiple segments are joined, region 2535, region 2533, and plug mandrel wire 2532 are attached to one another by any suitable means of bonding metal to metal, such as crimping, soldering, brazing, adhesives and the like. In one preferred embodiment, cyanoacrylate adhesives are used to adhere these various parts of sealing member 2530 to one another.
As illustrated in
As illustrated in
A lumen sealer portion 2536 is coaxially and fixedly mounted on wire 2532. Sealer portion 2536 forms a fluid tight seal with the outer diameter of wire 2532 and the inner diameter of lumen 2540, such that fluid introduced into lumen 2540 through the inflation port 1617 is prevented from flowing past sealer portion 2536 when sealer portion 2536 is inserted into lumen 2540 distally of the inflation port 1617. Sealer portion 2536 forms the fluid tight seal by firmly contacting the entire inner circumference of a section of lumen 2540 along a substantial portion of the length of sealer portion 2536.
As shown in
Catheter 1662 is changed from the valve open position to the valve closed position by the movement of sealing member 2530 and its various components. Preferably, the exact length of movement needed to change catheter 1662 from the valve closed to the valve open position is built into the movement function of the adaptor used to manipulate sealing member 2530 thereby opening and closing the catheter valve. In this regard, it is preferred that catheter 1662 be used with an adaptor such as adaptor 1630, which provides for such controlled precise movement.
The “stroke-length”, or overall movement in one dimension, of sealing member 2530 required to open or close the valve may be varied depending upon the catheter requirements. When relying upon the inflation adaptor to control movement, however, it is important that the movement of the controlling elements of the adaptor be coordinated with those of sealing member 2530.
Referring to
An actuator 1640, shown in
While the foregoing detailed description has described several embodiments of the apparatus and methods of the present invention, it is to be understood that the above description is illustrative only and not limiting of the disclosed invention. It will be appreciated that the specific dimensions of the various catheters and guidewires can differ from those described above, and that the methods described can be used within any biological conduit within the body and remain within the scope of the present invention. Thus, the invention is to be limited only by the claims which follow.
This application is a divisional of U.S. application Ser. No. 11/159,777, filed Jun. 23, 2005, which is a continuation of U.S. application Ser. No. 10/035,389, filed Dec. 28, 2001, now U.S. Pat. No. 6,958,059, which is a continuation-in-part of: U.S. application Ser. No. 09/537,471, filed Mar. 24, 2000, now U.S. Pat. No. 6,454,741, which is a continuation of U.S. application Ser. No. 09/049,857, filed Mar. 27, 1998, now U.S. Pat. No. 6,135,991, which is a continuation-in-part of U.S. application Ser. No. 08/813,807, filed Mar. 6, 1997, now abandoned; U.S. application Ser. No. 09/049,712, filed Mar. 27, 1998, now U.S. Pat. No. 6,544,276, which is a continuation-in-part of U.S. application Ser. No. 08/975,723, Nov. 20, 1997, now U.S. Pat. No. 6,050,972, which is a continuation-in-part of U.S. application Ser. No. 08/812,139, filed Mar. 6, 1997, abandoned, which is a continuation-in-part of U.S. application Ser. No. 08/650,464, filed May 20, 1996, now abandoned; U.S. application Ser. No. 09/438,030, filed Nov. 10, 1999, now U.S. Pat. No. 6,652,480; U.S. application Ser. No. 09/270,150, filed Mar. 16, 1999, now abandoned; U.S. application Ser. No. 09/837,872, filed Apr. 17, 2001, now abandoned, which is a continuation of U.S. application Ser. No. 09/415,607, filed Oct. 8, 1999, now U.S. Pat. No. 6,217,567, which is a continuation of U.S. application Ser. No. 08/812,876, filed Mar. 6, 1997, now U.S. Pat. No. 6,068,623; and U.S. application Ser. No. 09/314,054, filed May 18, 1999, now abandoned, which is a continuation of U.S. application Ser. No. 08/812,570, filed Mar. 6, 1997, now U.S. Pat. No. 6,022,336, which is a continuation-in-part of U.S. application Ser. No. 08/650,464, filed May 20, 1996, now abandoned; all of which are incorporated by reference in their entireties.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11159777 | Jun 2005 | US |
| Child | 11416365 | May 2006 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10035389 | Dec 2001 | US |
| Child | 11159777 | Jun 2005 | US |
| Parent | 09049857 | Mar 1998 | US |
| Child | 09537471 | Mar 2000 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 09537471 | Mar 2000 | US |
| Child | 10035389 | Dec 2001 | US |
| Parent | 08813807 | Mar 1997 | US |
| Child | 09049857 | Mar 1998 | US |
| Parent | 09049712 | Mar 1998 | US |
| Child | 09049857 | Mar 1998 | US |
| Parent | 08975723 | Nov 1997 | US |
| Child | 09049712 | Mar 1998 | US |
| Parent | 08812139 | Mar 1997 | US |
| Child | 08975723 | Nov 1997 | US |
| Parent | 08650464 | May 1996 | US |
| Child | 08812139 | Mar 1997 | US |
