1. Field of the Invention
The technical field of the present invention relates to medical guidewires and access systems.
Medical guidewires are typically used to access areas of interest in the body for diagnostic, interventional and surgical procedures and the like. Guidewires are usually the first used first to access a site of interest in a body lumen and then as a rail to slide diagnostic and interventional catheters and devices to the site. Various guidewire sizes have been produced for different anatomical and procedural situations. Typically, guidewires have a stiff proximal section to enhance axial pushability and rotational torque and a flexible distal portion to accommodate tortuosity. Guidewires typically have a floppy tip or other soft structure at the distal end to prevent trauma.
Because there are so many anatomical and procedural situations, there are large number of guidewire designs with diameters typically ranging from 0.010 inch to 0.038 inch and lengths ranging from 90 cm to 300 cm or more, with different grind profiles, coatings, and radiopaque tips. These parameters are well known to those familiar in the art.
Some recent efforts have been made to design guidewires with variable parameters than can be changed during a procedure to adjust to fit anatomical and procedural situations. More specifically guidewires have been designed to provide a varying level of stiffness or flexibility at certain sections of the guidewire. These adjustable guidewires are typically constructed of coaxial guidewires and tubes, with a guidewire being moved inside a tube to provide different flexibilities. However, these adjustable guidewires are limited by high friction between internal guidewire and tube, as well as how much adjustment can be accomplished.
One particular challenge for conventional guidewires is the introduction of a diagnostic catheter into the common carotid artery from the aortic arch, which challenge can be exacerbated by disease, and it's common to use a very stiff/supportive guidewire, such as a 0.35 inch guidewire. Guidewire placement cannot usually be achieved in these situations because the tortuosity will limit wire advancement and/or the wire will displace the diagnostic catheter from its position in the difficult anatomy. Therefore, the procedure will either become prolonged due to repeated attempts at access (exposing the patient to increasing risk of complication), or cannot proceed due to a failure of placement and a lack of subsequent access with an interventional guide or sheath.
To overcome this difficulty, Cardaioli et. al. (2009) J. Endovasc. Ther. 16:649-651, have proposed placing multiple 0.035 access guidewires from the aortic arch to the internal carotid artery in order to place a large guiding catheter that can accommodate several 0.035 wires. This approach, however, requires placing a larger introducer sheath which cannot be done in every patient, and interventionalists generally prefer to use smaller catheters until access is guaranteed because of risks of larger catheters.
Another challenging use for conventional guidewires is the interventional treatment of mesenteric pathology, e.g. oncologic, aneurysmal, atherosclerotic/obstructive, etc. For example, the placement of stent-grafts (generally large and stiff devices) in a highly tortuous splenic artery can be very difficult. Use of a stiff guidewire, such as a 0.035 inch guidewire, can straighten the artery making placement of the stent-graft difficult due to the creation of a pseudo-stenosis and loss of both anatomic landmarks and normal flow.
Another challenge arises from the numerous separate, time consuming, steps that can prolong the placement of stent-grafts in abdominal aortic aneurysms. Specifically, placement of a contralateral leg of such stent-grafts can require many steps and multiple guidewire exchanges in order to confirm intra-graft position, establish a marker system for required angiographic distance assessment, and then to locate a very stiff guidewire to allow advancement of the catheter curing the contralateral stent-graft.
A further challenge for conventional guidewires is the placement of an access guidewire into the iliac and femoral arteries from the contralateral femoral artery via the aortic bifurcation when the birfurcation is acute, calcified, or of a difficult geometry.
Another difficult challenge for interventionalists and surgeons is the access of a contralateral gate of a bifurcated stent graft for treatment of abdominal aortic aneurysms. During these procedures it is often necessary to place a guidewire in the contralateral gate, and verify that it is properly inside via two dimensional x-ray imaging.
Yet another challenge for interventionalists is the inability to inject contrast media for fluoroscopic (x-ray) visualization during placement of a 0.035 guidewire via a small 5-6 French diagnostic or guiding catheter. The small lumens of these catheters accommodate only the guidewire which substantially limits introduction of contrast media for distal visualization.
For these reasons, it would be desirable to provide a highly adjustable, easy and intuitive to use, low friction guidewire system that can accommodate almost any anatomical challenge. In particular, it would be desirable to provide guidewires and guidewire systems which can provide excellent trackability and necessary support while minimizing the stiffness of the guidewires or guidewire system to limit straightening of the target anatomy. It would be further desirable that the guidewires and guidewire systems could be used in a variety of anatomies, including at least for access to carotid arteries, for placement of stent-grafts in aneurysms, including both splenic aneurysms and abdominal aortic aneurysms, and elsewhere. It would be still further desirable if the deployment of the guidewires and guidewire systems were simplified to reduce the number of steps required for placement prior to introduction of the desired interventional or other catheter. It would be still further desirable if a guidewire system allowed contrast media to be injected through a standard 5-6 French diagnostic or guiding catheter during placement of wires in difficult anatomy. At least some of these objectives will be met by the inventions described below.
2. Description of Background Art
Cardaioli et al. (2009) J. Endovasc. Ther. 16: 649-651 has been described above. A guidewire control station used for managing multiple guidewires for bifurcated stent delivery is described in U.S. Pat. No. 7,645,273 and U.S. 2006/0074484. Variable stiffness guidewires are described in U.S. Pat. No. 7,402,141 and U.S. 2010/0305475.
According to the present invention, a medical guidewire system comprises a plurality of parallel relatively small guidewires which can be individually manipulated for wire deployment and, after wire deployment, utilized as one combined, larger guidewire for placement of an interventional or therapeutic catheter. By “relatively small,” it is meant that the individual wires are of a lesser caliber than the nominal internal diameter catheter in which they are intended to be used. The guidewire systems of the present invention will typically be placed through a pre-placed diagnostic or other catheter or sheath which is located at a target region in a patient's vasculature. Although exemplified by use in the vasculature, the systems and methods of the present invention could also find use in other body lumens, such as in the urinary tract. A plurality of individual guidewires, each of which will usually have a diameter below 0.031 inch, usually below 0.025 inch, more usually below 0.018 inch, frequently being 0.014 inch or smaller, are initially introduced to the diagnostic or other catheter using a guidewire jacket which is typically a tubular body which surrounds and constrains the multiple guidewires being introduced. The guidewire jacket is first introduced into the diagnostic or the catheter, and the multiple guidewire then advanced through the jacket and through the diagnostic catheter until they reach a location near a distal end of the diagnostic catheter. Then, individual ones of the multiple guidewires may be advanced beyond the diagnostic catheter to the target region in the vasculature until two, three, four, or more individual guidewires have all been located at the target region. After the multiple guidewires are properly located, the jacket and/or diagnostic catheter may be removed over the guidewires, leaving the multiple guidewires in place and available for use as a combined or assembled guidewire system. A desired interventional catheter, sheath, or other interventional tool may then be advanced over the combined guidewire assembly, and a subsequent treatment, intervention, or diagnosis at the target region may be performed using the guidewire, catheters, sheaths, and/or tools. The use of multiple, small diameter, guidewires has been found to provide both trackability and support equivalent to those achieved with larger guidewires while presenting a much less stiff structure in regions of tortuosity and facilitating placement. The multiple guidewire assemblies will often also occupy less cross-section while in the jacket or diagnostic catheter, precipitating the introduction of contrast or other media through the jacket and/or diagnostic catheter.
In a first specific aspect of the present invention, a guidewire system comprises a guidewire jacket, at least two guidewires, and optionally a handle. The guidewire jacket has a proximal end, distal end, and a connector hub at its proximal end. The at least two guidewires are slidably received in a lumen of the guidewire jacket, and each guidewire has a length which is greater than twice that of the guidewire jacket. The optional handle removeably receives each guidewire and may include a distal connector which detachably attaches to the connector hub on the guidewire jacket.
As described in greater detail below in connection with the methods of the present invention, the connector hub on the guidewire jacket may be attached to a proximal end of a pre-placed diagnostic or other catheter after the guidewire jacket has been fully inserted into the pre-placed catheter. The handle may then be used to simultaneously advance the at least two guidewires fully into the guidewire jacket and the diagnostic catheter, and the distal connector on the handle may then be attached to the connector hub on the jacket, thus allowing individual guidewires to be removed from the handle and manipulated while the other guidewires remain attached to the handle and immobilized relative to the guidewire jacket, diagnostic catheter, and vasculature. Such a construction greatly simplifies the placement and use of the individual guidewires making placement of multiple guidewires manageable by even less experienced physicians.
In particular embodiments of the guidewire systems of the present invention, a distal region of the guidewire jacket will consist of a tubular element which is free from exterior structure, such as balloons. The distal region of course may include other integrated features, such as radiopaque markers and alike. In other specific embodiments, the proximal connector on the guidewire jacket will comprise a luer and the distal connector on the handle will comprise a Touhy Borst valve. A removable retainer will typically be provided to hold a distal region of each guidewire to the connector hub on the guidewire jacket so that the guidewires remain fixed relative to the guidewire jacket while the jacket is being advanced into the diagnostic catheter.
In a still further specific embodiment of the guidewire system of the present invention, the system will be assembled for use with the distal tips of the guidewires received in a proximal end of the guidewire jacket lumen. The removable retainer will also be in place holding the guidewires, and the handle will be positioned proximally of the retainer and the connector hub so that the guidewire jacket may be placed into the diagnostic or other catheter, the connector hub attached to a hub on a catheter, and the retainer remove. The handle may then be advanced to introduce the guidewires through the guidewire jacket lumen. Such pre-assembled guidewire systems may be maintained in sterilized condition within a suitable medical device container, such as a box, tray, bag, or the alike.
The individual guidewires of the guidewire system of the present invention will usually be relatively flexible, typically having diameters in the ranges set forth above, and in some cases from 0.005 inch to 0.030 inc. Usually, however, at least one of the guidewires will have a stiffness which is greater than that of at least one other guidewire. In an exemplary systems, there will be one relatively stiff guidewire, and two relatively flexible guidewires in a single system, although other systems may comprise at least one relatively flexible guidewire and two relatively stiff guidewires. The guidewires may further comprise removable torquers attached to each guidewire. The systems may still further comprise a guidewire loop which receives proximal ends of the guidewires which extend proximally from the handle to assist in management. In still further specific embodiments, the guidewire system will comprise at least one larger guidewire having a distal diameter in the range from 0.014 inch to 0.028 inch and at least one smaller guidewire having a distal diameter in the range from 0.009 inch to 0.018 inch. Such system may consist of the one larger guidewire and two smaller guidewires and no additional guidewires or may consist of the one smaller guidewire and two larger guidewires and no additional guidewires. In other systems, all guidewires may be of the same diameter and ther may be from two to five total guidewires.
In a further specific embodiment of the guidewire system of the present invention, the system will consist of one larger diameter guidewire and one smaller diameter guidewire having pigtail distal end, usually being pre-shaped. At least one of these two guidewires will also usually have radiopaque markers at or near their distal end(s). Such guidewire systems are particularly suitable for assisting in placement of stent-grafts in abdominal aortic aneurysms.
In a second specific aspect of the present invention, methods for advancing catheter through a patient's vasculature or other body lumens are provided. A guidewire jacket is introduced into a lumen of a first catheter which was pre-placed into the vasculature to reach a target region. A first guidewire is advanced from the guidewire jacket into and through the first catheter lumen to the target region. A second guidewire also advanced from the guidewire jacket into and through the first catheter lumen to the target region in parallel to the first guidewire. Optionally, third, fourth, fifth, and additional guidewires could also be advanced, although usually no more than four guidewires would be advanced in total. After the guidewires are advanced and located, the first catheter and optionally the guidewire jacket are removed, leaving the guidewires in place. The jacket may optionally be left in place over the guidewires, but it will be eventually be necessary to remove any proximal hub or other structure from the jacket if the jacket is to remain in place when a interventional, therapeutic, or other catheter is advanced over the guidewire/jacket assembly. A second catheter may then be advanced over the parallel guidewires (and optionally jacket) to the target region. As discussed above in connection with the system of the present invention, the use of multiple parallel guidewires can provide excellent support and trackability while minimizing guidewire stiffness and limiting the risk of guidewire displacement as a second catheter is advanced.
In specific embodiments, introducing the guidewire jacket may comprise connecting a proximal end of the guidewire jacket to proximal end of the first catheter. Distal regions of the guidewires are detachably attached to the proximal end the guidewire jacket, and the guidewires may be detached from the proximal end of the guidewire jacket after the guidewire jacket has been introduced into the lumen of the first catheter but prior to advancing the individual guidewires to the target region.
In further specific aspects of the methods herein, a middle section of each guidewire maybe detachably attached to a handle which allows the guidewires to be simultaneously advance through the guidewire jacket by, in turn, advancing the handle relative to the guidewire jacket. The middle sections of the guidewires to which the handles detachably attached are usually located proximally of the distal end of each guidewire at a distance which positions the distal ends of the guidewires near the distal end of the guidewire jacket when the handle is fully advanced. After the handle has been fully advanced, individual guidewires are detached from the handle, and the detached guidewire manipulated while the other guidewire(s) remain attached to the handle.
Use of a Touhy Borst valve on the handle allows the delivery of contrast medium through the guidewire jacket through the target region when the handles attached to the guidewire jacket. Because the assembly of two or more small wires creates cross-sectional spaces inside a catheter lumen, these spaces allow for introduction of contrast media fluid.
In a still further specific embodiment, the first catheter comprises a diagnostic catheter placed from an aortic arch to a carotid artery. The second catheter delivers a stent to the carotid artery to treat the carotid artery disease.
In a still further specific embodiment, the first catheter comprises a diagnostic catheter disposed in a splenic artery and the target region is an aneurysm. The second catheter is used to deliver a stent-graft to the aneurysm in the splenic artery.
In a still further embodiment of the present invention, the target region comprises a contralateral gate in a stent-graft pre-placed in an aneurysms in the abdominal aortic. A distal end of the first catheter may be placed near but not through the contralateral gate, and the first guidewire is advanced through the gate. First catheter is then advanced over the first guidewire through the gate and into the stent-graft. The first and second guidewires are advanced from the jacket, through the stent-graft so that markers present on the guidewires are visible from the stent-graft contralateral gate to the associated iliac artery. The first catheter and guidewire jacket may then be removed from over the first and second guidewires. The second catheter then typically delivers a contralateral stent-graft to the contralateral gate of the main stent-graft body.
The object of the present invention is to provide an adjustable, easy to use guidewire system that will be able to access most anatomical structures, and provide a capable rail to assist in bringing other catheters, sheaths, and interventional tools to the required sites. In one embodiment, two or more small guidewires of similar geometry are provided side by side inside a tubular jacket, as shown in
Most current state of the art medical guidewires that are used in the beginning of many medical procedures are approximately 1.0 mm in diameter and more specifically 0.035 inch to 0.038 inch in diameter. In addition, most current state of the art guidewires used to transition interventional devices for cardiology and peripheral interventions and the like are smaller, for example 0.018 inch to 0.014 inch in diameter. In contrast, the present invention provides a plurality of smaller guidewires inside a thin flexible tube to match the larger diameter access guidewires. Therefore a parallel and plurality guidewire system can be used first to access the site of interest, and subsequently any guidewire than is no longer required for support well as the outer tube can be removed to leave one smaller guidewire that can be used to deliver interventional devices.
Some parameters that affect the performance of any one guidewire in the system are the diameter of the guidewire at any point in the length of the guidewire and more specifically the proximal section of guidewire; the design of a taper from a larger diameter to a smaller diameter, the starting position of a taper, the length and diameter of a reduced diameter at the smaller end of a taper, the material the guidewire is made from, and lubrication on the guidewire and location thereof. Some parameters that affect the performance of a system of parallel and plural guidewires are the contact area between each guidewire, the contact area of the guidewires to a tube jacket enclosing the guidewires if a jacket is used, lubrication used on the guidewire and the location of such lubrication, the position of features such as tapers relative to each guidewire, and the position of different zones of flexibility relative to each guidewire, the clearance of each guidewire to each other and to the jacket if a jacket is used, the material characteristics of a jacket if a jacket is used. Thus it can be seen that systems can be made of two or more guidewires of different diameters, and each guidewire can also have different profiles as well. Further, these guidewires can be provided in a system at the start of a procedure in an optimum position relative to an enclosing jacket tube for the start of the procedure, and then each guidewire can be manipulated axially for optimum performance of the system depending on the anatomical requirements and the procedural requirements at any point in time. Thus it should be clear that a system of parallel guidewires of even two or three guidewires can provide a very large variation of configurations that can be optimized quickly and easily to meet many anatomical challenges simply by moving the guidewires relative to each other.
A simple example of the present invention includes two or three guidewires of conventional geometry, such as guidewires 10, 11, and 12 shown in
A further advantage of the invention is that each guidewire has very low contact area relative to each other, as compared to a coaxial guidewire system such as a guidewire in a tube. This low contact area means that there is very low friction between each guidewire. In
A further reduction in friction between the plurality of guidewires and the tube jacket can be accomplished by coating the guidewires with friction reducing materials such as PTFE, hydrophilic coatings, and the like which are common and well known to those familiar to the art. It may be desirable to coat only certain sections of the guidewire with highly lubricious coatings, and have other sections with minimal or no lubrication. For example, looking again at
Referring now to
The handle 410 will typically have a U-shape body or structure with a distal connector 414 at its distal end. The distal connector 414 is intended to detachably attach to the connector hub 412 on the guidewire jacket 402 and will thus typically be a luer connector which mates with the luer on the guidewire jacket. The handle 410 will optionally further include a Touhy Borst valve 416 also usually at the distal end and adjacent to the distal connector 414. The Touhy Borst valve 416 has a fluid connector line 420 and hub 422 which allows connection of the valve 416 and connector 414 to a fluid source, such as a source of radio contrast fluid. In this way, the radio contrast and other fluids may be delivered to and through the guidewire jacket 402 for various conventional purposes during the protocols described here and after.
The handle 410 also has a proximal member 417 which includes a plurality of curved slots 419 (
A removable retainer 418 is detachably secured to both the connector hub 412 of the guidewire jacket 402 and to distal regions of each of the guidewires 404, 406, and 408. When the retainer 414 is in place, as shown in
As shown in
As shown in
Guidewire system 400 also includes a guidewire race 430 as shown in
Referring now to
To introduce the contralateral leg of the stent-graft, a pair of guidewires 440 and 442 (
The wires 404, 406, and 408 are then advanced simultaneously using the handle 410 until the distal connector 414 on the handle reaches and connects to the connector hub 412 on the guidewire jacket 402. As also shown in
Once placement of the wires 440 and 442 has been confirmed, the guidewire jacket 402 and diagnostic catheter 424 may be removed, conveniently using handle 402 to withdraw them over the wires. The wires are then available, as shown
A further alternative construction of the guidewire system of the present invention is shown in
First guidewire 508 and second guidewire 510 are illustrated as being partially advanced into the tubular body 503 of the guidewire jacket 502. Optionally, a guidewire retainer (not shown, but similar to retainer 418 illustrated previously) may be provided to immobilize the guidewires 508 and 510 onto the Touhy Borst connector 506 and/or luer 504. A first torquer 512 and a second torquer 514 are shown to be mounted on the first guidewire 508 and second guidewire 510, respectively, optionally, a guidewire organizer 516 may be employed, as shown in
Although specific anatomical situations are described herein, it should be clear to those versed in the art that there are many other body lumen presentations that the invention will have utility in. It should also be clear that although specific examples of the invention are disclosed, the invention is not limited to these descriptions and there are many versions of the invention that can be generated from the basic concept of using parallel guidewires of similar or different geometries, with or without being enclosed in a tube jacket, that can be encompassed and anticipated in the basic parameters of the invention.
This application claims the benefit of U.S. Provisional Application No. 61/556,181 (Attorney Docket No. 42807-703.101), filed Nov. 5, 2011, the entire contents of which are incorporated herein by reference.
Number | Date | Country | |
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61556181 | Nov 2011 | US |