The present invention relates to devices for treating body passages, and particularly catheter devices. Devices according to the invention are particularly useful for treating obstructions in blood vessels.
A wide variety of catheter devices for performing such operations are already known in the art. In order to be safely introduced into blood vessels, such devices must have relatively small diameters. However, they must also contain a number of lumens to provide at least one blood bypass flow passage, balloon inflation passages and treatment agent delivery passage, each of which must be dimensioned to allow an adequate flow of fluid. Given the constraints on the outer diameter of such a device, provision of the necessary number of passages, or lumens, creates certain difficulties.
Recent data suggests that heart attacks are caused by rupture of atherosclerotic plaques resulting in the formation of occluding clot. Statistically in 86% of heart attacks the obstruction by plaque is less than 70% and in 68% of cases less than 40%. A method to disintegrate clot while reducing or preventing microembolism of the distal circulation could be expected to provide a rapid and effectively treatment of heart attacks. Given the limitation of blood clot dissolving agents, such a device could prove to be life saving.
The present invention provides novel treatment devices having a reduced number of lumens, and thus alleviating a number of the problems that exist in the prior art.
A device according to the invention is provided for treating conditions causing obstructions in a body passage and is composed of: a first catheter dimensioned to be insertable into the body passage and having a lateral wall, a proximal end and a distal end; and a first balloon carried by the first catheter and extending outwardly from the lateral wall. The first catheter is provided internally with not more than three fluid conducting passages, including: a blood bypass flow passage extending at least from a first location between the first balloon and the proximal end to a second location at the distal end and communicating at the first location with a region surrounding the first catheter; a balloon inflation passage communicating with the first balloon; and a delivery/aspiration passage opening at the lateral wall at a location between the first location and the first balloon.
The invention further provides an apparatus for treating conditions causing obstruction in a body passage, comprising:
As shown in
Lumen 12 is provided with at least one blood inlet passage 26 located proximally of balloons 18 and 20. The distal end of lumen 12 is provided with at least one axial blood outlet opening 28, and possibly with one or more lateral blood outlet openings 30. Lumen 12 further constitutes a passage for a guidewire (not shown in
Lumen 16 is provided with at least one passage 34 via which lumen 16 communicates with a region that surrounds catheter 2 and that is enclosed between balloons 18 and 20.
Both lumens 14 and 16 are closed at their distal ends.
Catheter 102 includes a blood bypass flow lumen 112, a balloon inflation lumen 114 and a delivery/aspiration lumen 116. Catheter 102 carries, on its outer surface, two balloons 118 and 120.
Lumen 114 communicates with balloons 118 and 120 via respective passages 122 and 124. In order to equalize the pressure of the fluid supply to each of the balloons, passage 124 may have a larger cross section then passage 122. In addition, balloon 120 may be fabricated to have a higher compliance, i.e. a greater elasticity, than balloon 118. However, when the inflation fluid is a liquid, the fluid pressure in passages 122 and 124 will be substantially equal. Balloon 118 may be a low compliance pressure balloon. Alternatively, by making balloons 118 and 120 identical, i.e., of the same material and with the same dimensions, and locating each passage 122 and 124 symmetrically with respect to its associated balloon, i.e., so that the center line of the passage is equidistant from the proximal and distal lines of attachment of the balloon to the catheter, virtually equal inflation of the balloons can be realized.
Lumen 112 communicates with the region surrounding catheter 102 at a location proximal to balloon 118, via one or more inlet passages 126. The distal end of lumen 112 communicates with the region outside catheter 102 via an axial outlet opening 128 provided at the distal end of catheter 102 and possibly via one or more lateral outlet openings 130 that open at the lateral wall of catheter 102.
Lumen 116 communicates with a region surrounding catheter 102 and located between balloons 118 and 120 via a flow passage 134.
To assure that lumen 114 remains open in the region between balloons 118 and 120, catheter 102 may be strengthened in that region either by making catheter 102 slightly thicker in that region or by embedding a metal part, such as a titanium tube 140, at the time catheter 102 is formed by extrusion, or the catheter may be fabricated from a suitable plastic impregnated with titanium.
The device may be completed by a copper MRI transmit-receive coil 150 wound around the outer surface of catheter 102 in the region between balloons 118 and 120. Leads (not shown) for coil 150 may extend along catheter 102 to the proximal end thereof (not shown) for connection to conventional MRI components. This will allow MRI apparatus to be used to image the portion of the blood vessel wall between balloons 118 and 120 in order to provide information allowing proper positioning of catheter 102 and about the condition of the blood vessel wall in the region to be treated. For this purpose, the patient would be positioned so that the part of the patient's body that contains the vessel to be treated is enclosed by an annular magnet 152 that is needed to effect imaging and that is a standard component of existing MRI apparatus.
The device is completed by a guidewire 160 that extends through lumen 112. All of the illustrated lumens extend to a manifold (not shown) at the proximal end of catheter 102 in accordance with conventional practice in this art.
Catheter 102 can be introduced into a blood vessel to be treated in a conventional manner by first inserting guidewire 160 through guiding catheter 104 and then introducing catheter 102 over guidewire 160, i.e., by placing lumen 112 around guidewire 160 and through guiding catheter 104. Catheter 102 is advanced over guidewire 160 until reaching the location of the blood vessel where a treatment is to be performed. The positioning of catheter 102 may be aided by images produced by MRI equipment, as described above, and/or by providing radiopaque markers on either side of each balloon and employing fluoroscopic guidance.
When catheter 102 is properly positioned, balloons 118 and 120 are inflated by introducing inflation fluid through lumen 114 and passages 122 and 124. A variety of treatments may then be performed, such as disclosed in my issued U.S. Pat. No. 5,460,601, the contents of which are incorporated herein by reference. In the region between balloons 118 and 120, treatments with genes and chemotherapeutic drugs, thrombolytic drugs, anticoagulants and other forms of drug therapy, including treatments to passivate a clot site, can be carried out. Since the region of the blood vessel between balloons 118 and 120 is isolated from the remainder of the blood flow system, small quantities of a treatment agent can provide a high concentration at the treatment site.
The use of a single lumen for inflation of balloons 118 and 120 simplifies the structure of catheter 102 and provides additional space for the other lumens. It will be understood that the drawings do not necessarily show the lumens to scale and that the lumens can be given relatively large cross sections.
Since catheter 102 can be made smaller than prior art catheters having given lumen cross-sectional dimensions, it would further be possible to introduce a probe 170 that is housed within a sheath 172 of an ultrasonic system between catheters 102 and 104 and to bring the tip of this probe to the region to be treated, by extending the probe out of sheath 172 in order to supply ultrasonic energy that can potentiate the dispersal of drugs and genes into, and even through, the vessel wall at the treatment site. The ultrasonic energy may also be used to disintegrate plaque or clot. If confronted with certain conditions, such as an acute heart attack caused by extruded thrombus or clot, a suitable dissolution “cocktail” could also be introduced into the treatment region via lumen 116 and flow passage 134. One ultrasonic system that would be suitable for this purpose is disclosed in U.S. Pat. No. 4,870,953, the contents of which are incorporated herein by reference. In such a system, sheath 172 is provided with an annular passage for the flow of cooling medium to prevent overheating of probe 170 while in operation.
The tip of probe 170 can be moved into the region between balloons 118 and 120 either before the balloons have been inflated, or, if the balloons have already been inflated, they can be deflated briefly to allow the tip of probe 170 to be positioned between them. After the tip of probe 170 has been positioned, balloons 118 and 120 can be inflated. Balloon 118 will form a reasonably effective seal despite the presence of probe 170.
Catheter 204 carries a first balloon 218 and catheter 202 carries a second balloon 220, these balloons being identical to balloons 118 and 120 of the embodiment shown in
An inflation fluid flow passage 224 extends laterally between lumen 214 and the interior of balloon 220. Lumen 212 communicates with the region surrounding catheter 202 via one or several blood inlet flow passages 226 located proximally of balloon 220. The distal end of lumen 212 has at least an axial blood outlet opening 228 and may have one or more lateral blood outlet openings, as in the embodiment of
Catheter 204 is provided with one or several blood inlet flow openings 242 and carries, at its distal end, an annular seal member 244 that bears against the outer surface of catheter 202 to seal the annular space between catheters 202 and 204. Catheter 204 also carries a thin tube, or lumen, 246 for supplying inflation fluid to balloon 218.
Catheter 202 is displaceable in the axial direction relative to catheter 204 in order to vary the spacing between balloons 218 and 220, to thereby vary the size of the isolated treatment region between those balloons. When the arrangement shown in
The device shown in
Catheter 202 may also be provided with a MRI coil comparable to coil 150 of the embodiment shown in
All of the above-described embodiments of the invention are used in a similar manner in that they may all be introduced into the blood vessel via a guiding catheter, which may be catheter 104 of
If it is desired to perform a treatment with ultrasonic energy, the distal end of sheath 172 can be fitted in an opening provided in seal member 244, the opening being dimensioned to form a seal with the outer surface of the sheath.
Devices according to the invention can be used in conjunction with a variety of energy sources for disintegrating blockages including ultrasound devices, as mentioned above, laser devices and mechanical devices.
The embodiment shown in
The effectiveness of balloon 220 in pushing the clot toward balloon 218 can be enhanced by constructing balloon 220 so that when inflated it presents a concave surface toward balloon 218. Such a form of construction is shown in
For treatment of an acute heart attack where an arterial blockage is present, a catheter of the type disclosed herein could be inserted as a first treatment step and pushed across the blockage to provide immediate, temporary restoration of at least a limited blood flow.
A further embodiment of the invention will be described with reference to
The arrangement shown in
In an exemplary embodiment of the present invention, guiding catheter 410 may have a 6 Fr internal diameter, sheath 412 may have a one millimeter outer diameter, catheter 420 may have a 1-2 mm outer diameter and wire 414 may have a 0.014 inch outer diameter. The dimensions of wire 422 and its tip 424 will be selected in the basis of principles governing the design of ultrasonic vibration sources.
Wire 422 and tip 424, as well as the ultrasonic vibration generating components, may be constructed as disclosed in issued U.S. Pat. No. 4,870,953, the disclosure of which is incorporated herein by reference.
Filter 416 is composed of a flexible metal framework, or armature, carrying, at its distal side, which is at the right-hand side in
In order to treat an obstruction in a blood vessel, firstly, guide catheter 410 is introduced into the vessel upstream of the obstruction. Sheath 412 may be introduced simultaneously with, or subsequent to the introduction of, catheter 410. At the time that sheath 412 is introduced, filter 416 may be retracted into the distal end of the lumen in that sheath. After sheath 412 has been positioned, filter 416 is advanced out of the lumen in sheath 412 by moving wire 414 in the distal direction. Filter 416 is constructed to expand when not subjected to a compression force, i.e. to be unstressed when in its expanded state.
Normally, it will be desired to position filter 416 downstream of the obstruction before it is expanded. This is achieved by advancing sheath 412 to the right, past the obstruction, before advancing filter 416 out of and away from sheath 412. In
After filter 416 has been deployed, or expanded, to extend across the blood vessel downstream of the obstruction, wire 422 (shown in
Alternatively, as shown in
Here again, after disintegration of an obstruction has been completed, catheter 420 will be advanced in the distal direction in order to cause catheter 420 to slide around filter 416, thereby collapsing the filter into the associated lumen in catheter 420. After filter 416 has been brought completely into that lumen, catheter 410 and sheath 420 are withdrawn from the blood vessel and treatment is completed.
In further accordance with the invention, a treatment process can be carried out using, sequentially, either one of the devices shown in
The foregoing description of the specific embodiments will so fully reveal the general nature of the invention that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without undue experimentation and without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. The means, materials, and steps for carrying out various disclosed functions may take a variety of alternative forms without departing from the invention.
Thus the expressions “means to . . . ” and “means for . . . ”, or any method step language, as may be found in the specification above and/or in the claims below, followed by a functional statement, are intended to define and cover whatever structural, physical, chemical or electrical element or structure, or whatever method step, which may now or in the future exist which carries out the recited function, whether or not precisely equivalent to the embodiment or embodiments disclosed in the specification above, i.e., other means or steps for carrying out the same functions can be used; and it is intended that such expressions be given their broadest interpretation.
This application claims the benefit of U.S. Provisional Application No. 60/317,469, filed Sept. 7, 2001.
Number | Date | Country | |
---|---|---|---|
60317469 | Sep 2001 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 10200498 | Jul 2002 | US |
Child | 10981699 | Nov 2004 | US |