US20030208222A1 - Method and apparatus for emboli containment - Google Patents

Abstract

Disclosed herein is a catheter for use in an emboli containment system. In one embodiment, the catheter has a tubular body with a metallic braid construction. Two lumens extend through the tubular body, the lumen being in a side-by-side configuration. One of the lumens functions as an inflation lumen, and is in fluid communication with an inflatable balloon mounted on the distal end of the catheter. The second lumen is adapted to receive other therapeutic catheters which comprise the emboli containment system. In another embodiment, apparatus is provided for treatment of a stenosis in a lumen in a blood-carrying vessel comprising a main catheter and a therapeutic catheter. The main catheter comprises a first flexible elongate tubular member having proximal and distal extremities. A sealing element is carried on the distal extremity of the first flexible elongate tubular member. The first flexible elongate tubular member has a main lumen therein extending from the proximal extremity to the distal extremity and exits through the distal extremity. An adapter is mounted on the proximal extremity of the first flexible elongate tubular member. The therapeutic catheter comprises a second flexible elongate tubular member having proximal and distal extremities. An element for performing work is mounted on the distal extremity of the second flexible elongate tubular member. An adapter is mounted on the proximal extremity of the second flexible elongate tubular member. The second flexible elongate tubular member is slidably mounted in the main lumen of the first elongate tubular member. A mechanism is carried by the first flexible elongate tubular member for causing the sealing element to form an occlusion in the vessel proximal of the stenosis to provide a working space distal of the sealing element. A mechanism is coupled to the attachment of the therapeutic catheter for causing operation of the element for performing work in the working space adjacent the stenosis.

Description

CROSS REFERENCE TO RELATED APPLICATIONS
• This application is a continuation of application Ser. No. 08/813,023, filed on Mar. 6, 1997, which is a continuation-in-part of application Ser. No. 08/650,464 filed on May 20, 1996, the entirety of which is incorporated herein by reference, which is a continuation-in-part of application Ser. No. 08/464,579, filed Jun. 5, 1995, now U.S. Pat. No. 5,833,650.[0001]
BACKGROUND OF THE INVENTION
• The present invention generally relates to medical devices, and in particular, to catheters which can be used in an emboli containment system. This invention also relates to an apparatus and method for treating occluded vessels in living bodies and more particularly balloon catheters and balloon guide wires for treating occlusions in vessels in human bodies, as for example carotid arteries.[0002]
• Balloon angioplasty, and other transluminal medical treatments, are well-known, and have been proven efficacious in the treatment of stenotic lesions in blood vessels. The application of such medical procedures to certain blood vessels, however, has been limited, due to the risks associated with creation of emboli during the procedure. For example, angioplasty is not the currently preferred treatment for lesions in the carotid artery, because of the possibility of dislodging plaque from the lesion, which can enter the various arterial vessels of the brain and cause permanent brain damage. Instead, surgical procedures are currently used, but these procedures present substantial risks.[0003]
• One solution to this problem is the use of a multi-catheter emboli containment system, as disclosed in the above-referenced application Ser. No. 08/650,464. As disclosed therein, a treatment chamber within a blood vessel is formed by two occlusion balloons on opposite sides of a stenotic lesion, thereby preventing emboli migration during the treatment procedure. The chamber is created by two occlusion balloon catheters which are slidably disposed with respect to one another.[0004]
• Emboli containment procedures of this type are advantageous, because they permit the clinician to utilize the benefits of transluminal treatment in a wider variety of blood vessels. However, the procedures require the complex coordination of multiple catheters. Consequently, it is desirable to have catheters which make it easier for the clinician to utilize an emboli containment system. It is also desirable that the catheters used in the emboli containment system have a high degree of flexibility, to navigate tortuous blood vessel networks.[0005]
• Consequently, there exists a need for improved emboli containment catheters. This is especially true in the context of the “main” catheter, through which other catheters are inserted and controlled to form the emboli containment system. There is also a need for new and improved apparatus and methods which make it possible to treat occluded vessels without endangering the patient.[0006]
SUMMARY OF THE INVENTION
• The present invention advantageously provides as a main catheter an occlusive device adapted for use in a multi-catheter emboli containment system. In one aspect of the present invention, there is provided a catheter, comprising an elongate flexible tubular body having a proximal end and a distal end. The tubular body incorporates a metallic member, which may comprise a braid or a coil. A main lumen and an inflation lumen extend through the tubular body, and are in a side-by-side configuration. The main lumen is sized to receive a therapeutic and/or diagnostic device such as a balloon angioplasty catheter or an atherectomy catheter. The tubular body is provided with a manifold. The manifold has an aspiration port which is in fluid communication with the main lumen. The distal end of the tubular body also has a tip formed of a more flexible material than that used to form the tubular body.[0007]
• In one preferred embodiment, an inflatable balloon is mounted on the distal end of the tubular body. An inflation port is also provided on the manifold in this embodiment. The inflation port is in fluid communication with the inflation lumen. In this embodiment, the inflatable balloon is formed of a block copolymer of styrene-ethylene-butylenestyrene.[0008]
• In another preferred embodiment, the metallic braid or coil is formed of a metal selected from the group consisting of 304, 316, or 400 series stainless steel, nitinol, platinum, gold, Elgiloy™, or combinations thereof. Where a metallic braid is used, it may optionally have a braid density at a first point on the tubular body that is greater than the braid density of the metallic braid at a second point on the tubular body by at least 20 picks per inch. Similarly, where a metallic coil is used, it may optionally have a coil density at a first point on the tubular body that is greater than the coil density at a second point on the tubular body.[0009]
• In another aspect of the present invention, there is provided a catheter comprising an elongate flexible tubular body having a proximal end and a distal end. Alternatively, there may be provided a circular cross-sectional configuration at the proximal end which is continuous with a distal end having a reduced internal and outer tubular body diameters. A first and second lumen extend through the tubular body from the proximal end to the distal end in a side-by-side configuration. The first lumen has a generally circular cross-sectional configuration at the proximal end and a generally oval cross-sectional configuration at the distal end. The second lumen has a diameter no smaller than 0.05 inches, preferably no smaller than 0.08 inches, and is adapted to slidably accommodate a therapeutic or diagnostic device.[0010]
• In one preferred embodiment, an inflatable balloon is mounted on the distal end of the tubular body. The inflatable balloon is in fluid communication with the first lumen, such that fluid passing through the first lumen may be used to inflate or deflate the inflatable balloon. The second lumen size may vary in certain embodiments, such that in one embodiment, the second lumen has a diameter no smaller than about 0.05 inches, and is preferably no less than 0.080 inches.[0011]
• In another aspect of the present invention, there is provided a catheter with variable stiffness, comprising a tubular body having a proximal end and a distal end. A metallic braid or metallic coil is within the tubular body. In one embodiment, the proximal end of the tubular body has a lower braid or coil density than the distal end. In another embodiment, the braid or coil density is kept constant along the length of the tubular body, and the tubular body is formed of materials with greater stiffness at the proximal end. In another embodiment, a combination of braids and coils of varying density can be used at various points along the tubular body, to create a catheter tubular body having a more flexible distal end.[0012]
• In another aspect of the present invention, there is provided a method of making a catheter tubular body. The method comprises providing a first polymeric tube formed of a first material having a first melting point. The first polymeric tube is then inserted into a second polymeric tube to form a combined tube. The second polymeric tube is formed of a second material having a second melting point which is less than the first melting point. The combined tube is then placed adjacent to a third tube. The third tube is formed in part of the second material. The tubes are then heated to a temperature greater than the second melting point but less than the first melting point, such that the combined tube melt fuses with third tube to form a catheter tubular body having two lumen extending therethrough in a side-by-side configuration. The first material may be selected from the group comprising polyimide, polyamide, PET and PEEK, blends thereof and the second material may be selected from the group comprising Pebax™, polyethylene, nylon, or Hytrel™ or blends thereof. Preferably, the temperature of the heating step is from about 250° to 600° F. It is also preferred that the third tube incorporate a metallic member, such as a braid or coil.[0013]
• In general, 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.[0014]
• Another object of the present invention to provide an apparatus or assembly and method of the above character which makes it possible to perform therapeutic procedures without using perfusion.[0015]
• 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.[0016]
• 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.[0017]
• 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.[0018]
• 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.[0019]
• 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.[0020]
• 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.[0021]
• 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.[0022]
• 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.[0023]
• 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.[0024]
• 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.[0025]
• 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.[0026]
• Another object of the invention is to provide an apparatus and method of the above character which makes it possible to treat stenoses or occlusion in the vessel which are normally not accessible for surgical procedures.[0027]
• 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.[0028]
• 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.[0029]
• 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.[0030]
• 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.[0031]
• 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.[0032]
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a side view of an embodiment of the catheter of the present invention.[0033]
• FIG. 2 is a cross-sectional view of catheter of FIG. 1 along lines[0034]2-2.
• FIG. 3 is a cross-sectional view of the catheter of FIG. 1 along lines[0035]3-3.
• FIG. 4 is a longitudinal cross-sectional view of the distal end of the catheter of FIG. 1.[0036]
• FIG. 5 is an enlargement of the region circumscribed by lines[0037]5-5 of the catheter of FIG. 4.
• FIG. 6 is an illustration of the catheter of the present invention as used in an emboli containment system.[0038]
• FIG. 7 is a cross-sectional view of the emboli containment system of FIG. 6 along lines[0039]7-7.
• FIG. 8 is a cross-sectional view of the emboli containment system of FIG. 6 along lines[0040]8-8.
• FIG. 9 is a cross-sectional view of the emboli containment system of FIG. 6 along lines[0041]9-9.
• FIGS.[0042]10A-E illustrate the use of an embodiment of the catheter of the present invention in an emboli containment treatment procedure.
• FIG. 11 is a side-elevational view partially in section showing the catheter apparatus or assembly of the present invention for treating occluded vessels.[0043]
• FIG. 12 is a cross-sectional view taken along the line[0044]12-12 of FIG. 11.
• FIG. 13 is a cross-sectional view taken along the line[0045]13-13 of FIG. 11.
• FIG. 14 is a cross-sectional view taken along the line[0046]14-14 of FIG. 11.
• FIG. 15 is a schematic illustration of how the catheter apparatus shown in FIG. 11 is deployed in a carotid artery.[0047]
• FIGS.[0048]16A-16E are illustrations showing the various steps utilized in deployment of the catheter apparatus in performing the method of the present invention in a vessel where a bifurcation is not present.
• FIG. 17 is a side-elevational view partially in section of another embodiment of a catheter apparatus or assembly incorporating the present invention for treating occluded vessels using an atherectomy device.[0049]
• FIG. 18 is a cross-sectional view taken along the line[0050]18-18 of FIG. 17.
• FIG. 19 is a cross-sectional view taken along the line[0051]19-19 of FIG. 17.
• FIG. 20 is a side-elevational view in section of the distal extremity of another embodiment of a catheter apparatus incorporating the present invention and utilized for delivering an expandable stent to a stenosis.[0052]
• FIG. 21A is a schematic illustration showing the manner in which the apparatus of the present invention is utilized in connection with vessels of a patient in performing the method of the present invention.[0053]
• FIG. 21B is an additional partial schematic illustration showing interconnections in the catheter apparatus shown in FIG. 21A.[0054]
• FIG. 22 is a plan view of another embodiment of a catheter apparatus incorporating the present invention.[0055]
• FIG. 23 is a cross-sectional view taken along the line[0056]23-23 of FIG. 22.
• FIG. 24 is an end elevational view looking down the line[0057]24-24 of FIG. 22.
• FIGS. 25A, B, C, and D are illustrations or cartoons showing the method of the present invention being utilized with the apparatus shown in FIG. 21 in a vessel having a bifurcation therein.[0058]
• FIG. 26 is a side-elevational view of a main catheter incorporating the present invention.[0059]
• FIGS. 26A and 26B are partial side-elevational views of the distal extremities showing alternative embodiments of the main catheter of the present invention incorporating, respectively, Judkins left shape and Judkins right shape in their distal extremities.[0060]
• FIG. 27 is a cross-sectional view taken along the line[0061]27-27 of FIG. 26.
• FIG. 28 is a cross-sectional view taken along the line[0062]28-28 of FIG. 26.
• FIG. 29 is an enlarged partial cross-sectional view of the distal extremity of the catheter shown in FIG. 26.[0063]
• FIG. 30 is a side-elevational view of the balloon-on-a-wire construction incorporating the present invention.[0064]
• FIG. 31 is a cross-sectional view taken along the line[0065]31-31 of FIG. 30.
• FIG. 32 is an enlarged cross-sectional view of the distal extremity of the construction in FIG. 30.[0066]
• FIG. 33 is a cross-sectional view similar to FIG. 32 but showing a different embodiment utilizing a twisted dual core.[0067]
• FIG. 34 is a cross-sectional view similar to FIG. 32 but showing the use of a twisted core.[0068]
• FIG. 35 is a cross-sectional view of the proximal removable fitting of the construction shown in FIG. 30.[0069]
• FIG. 36 is a side-elevational view partially in cross section of an irrigation catheter incorporation the present invention.[0070]
• FIGS. 36A and 36B are side-elevational views of the distal extremities of additional embodiments of irrigation catheters incorporating the present invention.[0071]
• FIGS.[0072]37-43 are cartoons showing the manner in which the apparatus of the present invention shown in FIGS.26-36 is used performing a therapeutic procedure in accordance with the present invention.
• FIG. 44 is a side-elevational view partially in cross-section of another embodiment of a main catheter incorporating the present invention.[0073]
• FIG. 45 is a side-elevational view partially in cross-section showing another embodiment of an irrigation catheter incorporating the present invention.[0074]
• FIGS.[0075]46-50 are cartoons showing the manner in which a therapeutic carotid procedure is performed in accordance with the present invention where there is a bifurcation.
• FIG. 51 is a side-elevational view partially in section of another embodiment of a balloon-on-a-wire incorporating the present invention.[0076]
• FIG. 52 is a cross-sectional view taken along the line[0077]52-52 of FIG. 51.
• FIG. 53 is a side-elevational view in section of another embodiment of a catheter apparatus incorporating the present invention for treating occluded vessels.[0078]
• FIG. 54 is a side-elevational view in section similar to FIG. 53 but showing the apparatus in FIG. 53 with the self-expandable sealing means deployed.[0079]
• FIG. 55 is a side-elevational view in section of another embodiment of a catheter apparatus incorporating the present invention for treating occluded vessels.[0080]
• FIG. 56 is a view similar to FIG. 55 but showing the self-expandable sealing means deployed.[0081]
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
• Referring to FIG. 1, there is depicted an embodiment of the balloon catheter of the present invention. Although illustrated and described below in the context of an emboli containment system featuring balloon dilatation treatment of a stenotic lesion, it is to be understood that the present invention can be easily adapted to a variety of emboli containment treatment applications. For example, the present inventors contemplate that the catheter of the present invention can be used in emboli containment treatment procedures which include atherectomy, stent implantation, drug delivery, as well as other applications. Furthermore, although depicted and described as a two lumen catheter, it should be appreciated that the present invention may also be adapted to catheters having more than two lumen. The manner of adapting the present invention to these various treatments and structures will become readily apparent to those of skill in the art in view of the description which follows.[0082]
• [0083]Catheter10 generally comprises an elongate flexibletubular body16 extending between aproximal control end12 and a distalfunctional end14.Tubular body16 has amain lumen30 which extends between ends12 and14.Main lumen30 terminates in aproximal opening23 and adistal opening27. Asmaller inflation lumen32, configured in a side-by-side relationship withmain lumen30, extends along the length oftubular body16 and may terminate within or near anocclusion balloon26 mounted on thedistal end14 ofcatheter10, as described below.Inflation lumen32 is in fluid communication withballoon26, such that fluid passing throughinflation lumen32 may be used to inflate or deflateballoon26. In some embodiments, the inflation lumen may originate at a point distal to theproximal end12, and extend distally from that point in a side-by-side configuration withmain lumen30.
• In some embodiments, instead of an[0084]occlusion balloon26,distal end14 is provided with a mechanical occlusive device such as a pull-wire activated braid which filters all particles larger than 12 microns. Alternatively, other occlusive filtering devices may also be used, as is known by those of skill in the art.
• A[0085]control manifold19 is provided at theproximal end12 ofcatheter10.Control manifold19 is generally provided with a number of ports to provide access to the catheter lumen. For example, for the embodiment depicted in FIG. 1,control manifold19 is provided with a catheter end-access port22 and a catheter side-access port24, to provide an introduction point for the insertion of other catheters intolumen30.Ports22 and24 are preferably provided with standard Touhy Borst connectors, although other sealing type connectors, such as a hemostasis valve, may be used.Manifold19 is also provided with anaspiration port20 which is in fluid communication withlumen30, for attachment of devices to aspirate fluid intoopening27, throughlumen30, and outport20. Aninflation port18, in fluid communication withlumen32, is further provided onmanifold18 for attachment of devices to inflate or deflateballoon26. In one preferred embodiment,ports18 and20 are provided with standard luer connectors, to facilitate attachment of standard inflation or aspiration apparatus, respectively, toports18 and20. Other embodiments ofcatheter10 may feature more or less ports, depending upon the number of lumen in the catheter and the desired functionalities of the catheter.
• [0086]Manifold19 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 fluid aspiration. In one preferred embodiment,manifold19 is integrally formed out of medical grade polycarbonate. Other suitable materials may be used to form manifold19, such as polyvinyl chloride, acrylics, acrylonitrile butadiene styrene (ABS), nylon, and the like.
• [0087]Manifold19 is attached totubular body16 so that the various ports are placed in communication with the appropriate lumen, as described above in connection with FIG. 1. Preferably, astrain relieving connector11 is used to join manifold19 totubular body16. For the embodiment depicted in FIG. 1,strain relieving connector11 consists of a length of flexible polymeric tubing, such as 40 durometer (D) Pebax™, or other polyether block amides, and other similar materials.Tubular body16 is inserted in one end ofstrain relieving connector11, and the other end ofstrain relieving connector11 is inserted intomanifold19. Suitable adhesives, such as a cyanoacrylate, epoxies, or uv curable adhesives, may be used tobond manifold19 to strain relievingconnector11. Alternately, manifold19 may also be insert molded with thetubular body16, as is known by those of skill in the art. Adhesives may also be used to bond thestrain relieving connector11 totubular body16, or alternately, conventional heat bonding, as known to those of skill in the art, may be used to attachtubular body16 to strain relievingconnector11.
• The length of[0088]tubular body16 may be varied considerably depending upon the desired application. For example, wherecatheter10 is to be used as part of an emboli containment system for treatment of carotid artery disease, withcatheter10 being introduced at the groin, the length oftubular body16 may range from 80 to 110 centimeters, and is preferably 95 cm. Other treatment procedures, requiring a longer or shortertubular body16, are easily accommodated by the present invention, by forming atubular body16 of the desired length during the manufacturing process.
• The outer diameter of[0089]tubular body16 may also be varied considerably, and in most cases, will depend upon the intended treatment procedure for whichcatheter10 will be used. That is, the outer diameter oftubular body16 must be large enough to be capable of forming amain lumen30 which can slidably accommodate the other catheters used in the emboli containment system, as described in detail below. However, the outer diameter oftubular body16 must also be smaller than the internal diameter of smallest blood vessel through whichcatheter10 passes during the selected treatment procedure. In general, the diameter ofmain lumen30 may range from at least about 0.05 inches to about 0.12 inches, and be capable of accommodating many types of catheters to be used therein, while still maintaining a low profile for the diameter oftubular body16.
• For many treatment applications, it has been found that a tubular body having an outside diameter of no more than about 0.135 inches (10 French) is preferred. Advantageously, with an outer diameter of this size,[0090]main lumen30 may have an internal diameter of about 0.10 inches, makinglumen30 capable of accommodating a wide variety of treatment catheters, or catheters used for diagnostic purposes. Of course, as will be appreciated by those of skill in the art, where the catheters intended to be inserted intolumen30 are known to have outer diameters significantly smaller than 0.10 inches, such thatlumen30 may be smaller than 0.10 inches and still accommodate them, atubular body16 having an outer diameter of less than 0.135 inches may be selected.
• Although not required, the interior surface of[0091]lumen30 may be provided with aliner35 formed of a lubricous material, to reduce the frictional forces between the lumen surface and the catheters which are inserted intolumen30. In one preferred embodiment,liner35 is formed out of polytetrafluoroethylene (PTFE). Lubricous materials other than PTFE, which are biocompatible, fairly flexible, and easily mounted to other polymeric materials of the type used to form catheter tubular bodies, may also be used to formliner35. Examples of such materials include polyethylene, Pebax™, nylon, and the like. Where increased flexibility of thedistal end14 ofcatheter10 is desired, Pebax™ may be used in place of PTFE along a selected portion ofdistal end14, such as the distal most 15-20 cm ofend14.
• To minimize the outer diameter of[0092]tubular body16, it is preferable thatinflation lumen32 be as small as possible in accordance with its function. That is,inflation lumen32 is preferably no larger than required to provide sufficient fluid to balloon26 for rapid inflation, or so that fluid may be quickly withdrawn fromballoon26 during deflation. For compliant expansion balloons of the type described below, inflation lumen diameters of from about 0.008 inches to about 0.018 inches are satisfactory, with a diameter of about 0.014 inches being preferred for some applications.
• Furthermore, in one embodiment, as illustrated in FIGS.[0093]1-3, the outer diameter oftubular body16 just proximal toballoon26 is minimized by providing an inflation lumen32awith an oval cross-sectional configuration, as illustrated in FIG. 3. Preferably, inflation lumen32ahas an oval cross-sectional configuration which extends proximally from theproximal edge balloon26 by a distance of at least 0.1 cm, more preferably 1 cm, and optimally by a distance equal to the length oftubular body16. For ease of manufacturing, the cross-sectional configuration oflumen32 at points further proximal toballoon26 may be generally circular, as illustrated in FIG. 2. Where the lumen configuration differs from proximal to distal end, as illustrated in FIGS. 2 and 3, a region oftransition33 is provided wherein the lumen configuration changes from circular to oval.
• It will be appreciated by those of skill in the art that other cross-sectional configurations of lumen[0094]32amay be provided and still function to reduce the profile oftubular body16. For example, triangular, rectangular, or other non-oval cross sectional configurations are easily adapted to lumen32a, and the manner of incorporating such alternative cross-sectional configurations will be readily apparent to those of skill in the art in view of the description which follows.
• A variety of different manufacturing methods may be used to alter the cross-sectional configuration of[0095]lumen32, as will be appreciated by those of skill in the art. In one preferred method,lumen32 is formed of a polymeric tube, such as a polyimide tube, which has been compressed at one end so that it has the desired oval shape. The polyimide tube is then inserted into a second tube formed of a material having a lower melting point than polyimide, such as 72D Pebax™. The combination is then heat bonded to another tube definingmain lumen30, such as a braided Pebax™ tube, as described below. The heat bonding takes place at a temperature greater than the melting temperature of Pebax™, but less than the melting temperature of polyimide, so that the Pebax™ tubes melt fuse to form the two lumen tubular body.
• Alternately, the cross-sectional configuration, as well as the cross-sectional area of[0096]lumen32, may also be altered by joining two separate polymeric tubes together to form acontinuous inflation lumen32. One of the tubes, corresponding to the proximal end ofcatheter10 as shown in FIG. 3, may have a circular cross-sectional configuration. The second tube, corresponding to the distal end ofcatheter10 as shown in FIG. 2, has an oval configuration. One end of a mandrel may be inserted into each of the tubes, and conventional heat bonding may be used to create the cross-sectional configuration transition. As before, the combined tube may then be heat bonded to a second tube definingmain lumen30 to formtubular body16.
• As illustrated in FIG. 1, an[0097]inflatable balloon26 is mounted on thedistal end14 ofcatheter10. In most applications wherecatheter10 is to be used in an emboli containment treatment procedure,inflatable balloon26 will function as an occlusion balloon, to prevent blood from passing through the blood vessel distal ofballoon26. Thus,inflatable balloon26 is preferably able to expand to fit a variety of different blood vessel diameters. Accordingly, it is preferred thatinflatable balloon26 have a compliant expansion profile, tending to increase in radial diameter with increasing inflation pressure. To achieve this,balloon26 may be made out of materials which impart such expansion characteristics, including elastomeric materials such as latex or silicone. In one preferred embodiment,inflatable balloon26 is formed out of a material comprising a block copolymer of styrene-ethylene-butylene-styrene, sold under the trade name C-Flex™. Further details as to balloons of this type are disclosed in our copending application entitled PRE-STRETCHED CATHETER BALLOON, Ser. No. 08/812,139, filed Mar. 6, 1997, now abandoned, the entirety of which is incorporated by reference.
• [0098]Inflatable balloon26 may be placed in fluid communication with lumen32avia a fill hole (not shown) extending throughtubular body16 withinballoon26, such that fluid may be introduced intolumen32 throughinflation port18 to inflateballoon26. Alternately, lumen32amay terminate withinballoon26, to provide the requisite fluid communication.Balloon26 may be attached totubular body16 by any suitable manner known to those of skill in the art, such as adhesives or heat bonding.
• [0099]Tubular body16 must have sufficient structural integrity, or “stiffness,” to permitcatheter10 to be advanced through vasculature to distal arterial locations without buckling or undesirable bending oftubular body16. However, it is also desirable fortubular body16 to be fairly flexible neardistal end14, so thattubular body16 may be navigated through tortuous blood vessel networks. Thus, in one preferred embodiment,tubular body16 is made to have variable stiffness along its length, with the proximal portion oftubular body16 being less flexible than the distal portion oftubular body16. Advantageously, atubular body16 of this construction enables a clinician to more easily inserttubular body16 into blood vessel networks difficult to reach by a tubular bodies having uniform stiffness. This is because the stiffer proximal portion provides the requisite structural integrity needed to advancetubular body16 without buckling, while the more flexible distal region is more easily advanced into and through tortuous blood vessel passageways.
• In one preferred embodiment, variable stiffness along the length of[0100]tubular body16 is achieved by forming a polymerictubular body16 which incorporates along its length a variable stiffness metallic member. The metallic member may comprise a braid or coil, and may have varying braid density or coil pitch at different points along the catheter tubular body. For example, as shown in FIGS. 2 and 3,tubular body16 may be provided with abraid36 incorporated into the wall structure oftubular body16. Referring to FIG. 1, to achieve variable stiffness, proximal region A ofcatheter10 is provided with ametallic braid36 having a lower braid density than that present in themetallic braid36aof distal region B. The lower braid density of proximal region A permits polymer flow in between the braids during the formation of the tubular body. Because the polymer is relatively stiffer than the braid, the lower braid density results in proximal region A being less flexible, or “stiffer”, than distal region B. In one preferred embodiment, the braid density of proximal region A varies from 60 to 80 picks per inch, while that of region B varies from 90 to 110 picks per inch.
• As will be appreciated by those of skill in the art, metallic members other than braids may be incorporated into[0101]tubular body16 to create variable stiffness. For example, a metallic coil may be introduced intotubular body16. The coil may have different pitch along the length oftubular body16, such that region A is provided with a coil having a lower pitch than that present in region B. The manner of adapting a coil, and other metallic members, to the catheter tubular body in place of a braid will become readily apparent to those of skill in the art in view of the description which follows.
• The precise density of the braiding provided to regions A and B can be varied considerably at the point of manufacture, such that catheters having a variety of different flexibility profiles may be created. Moreover, the braid density may be varied within catheter regions A and B as well, by providing a metallic braid which has a braid density gradient along its length. For example, the most proximal part of region A may be provided with a[0102]metallic braid36 having a braid density of about 60 picks per inch, with the braid density increasing distally at a certain rate so that the final pick count is not more than 110 picks per inch at the distal end.
• A variety of different metals, known to be ductile and shapeable into fine wires and flat ribbons, having a diameter of about 0.0005 inches to about 0.005 inches for wires, or the same thickness for a ribbon, may be used to form the[0103]metallic braids36 and36aor metallic coils. For example, stainless steel, platinum, gold and nitinol, or combinations thereof are all suitable metals. In one preferred embodiment,braid36 is formed of stainless steel, and has a braid density which varies from 70 picks per inch at the most proximal part of region A, to 100 picks per inch at the most distal part of region B.
• [0104]Metallic braids36 may be introduced into the structure oftubular body16 through conventional catheter forming techniques. For example,tubular body16 may be formed by braiding over a 72D Pebax™ tube that has a removable core mandrel in the internal diameter supporting the Pebax™ tube, and then inserting the braided tube into a 72D Pebax™ outer tube at the proximal region A and a 35D Pebax™ tube at the distal region B, so that the braid is sandwiched between the inner and outer tubes. A stainless steel support mandrel may be inserted into the removable core mandrel as additional support. A shaping container such as a fluorinated ethylene propylene (FEP) shrink tube is inserted over the outer Pebax™ tube, and the entire apparatus may then be placed in a hot box or oven kept at a temperature slightly greater than the melting temperature of the Pebax™ tubes. The Pebax™ tubes will melt and fuse together, and once cooled, will form a tubular body incorporating the metallic braid. The shaping container and mandrels may then be removed and discarded.
• In another embodiment, variable stiffness of[0105]tubular body16 may be achieved by forming regions A and B oftubular body16 out of polymeric materials having differing degrees of stiffness. For example, one half of an inner tube of 72D Pebax™ may be inserted into an outer tube of 35D Pebax™, and the other half of the inner tube may be inserted into a 72D Pebax™ outer tube. The combination may then be heat fused, as described above. The 35D/72D Pebax™ combination forms a more flexible tubular body than the region 72D/72D Pebax combination. More or less flexible materials may be used as desired to alter the flexibility of the resulting tubular body. Furthermore, the flexibility of the various regions of a tubular body formed in this manner may be varied further by incorporating a metallic member having either a uniform density, or a varying density, into the tubular body, as described above.
• In another preferred embodiment, variable stiffness along the length of the tubular body may be achieved by using different metallic members in regions A and B. For example, proximal region A may be provided with a multilayer coil, while distal region B may be provided with a braid. Alternately, proximal region A may be provided with a metallic braid, while distal region B may be provided with a single layer coil. As discussed above, the densities of the metallic members in the respective sections may be varied considerably to select for a desired variable stiffness profile, as will be appreciated by those of skill in the art.[0106]
• In one preferred embodiment, variable stiffness along the length of the tubular body is achieved by keeping the braid density constant along the length of[0107]tubular body16 and then forming the proximal and distal portions oftubular body16 of polymeric materials of differing stiffness. For example, braid density may be uniform and range from 60-80 picks/inch, more preferably be about 70 picks/inch, with region A being formed of 72D Pebax™ and region B being formed of 25-50D Pebax™. Alternately, region A can be formed of high density polyethylene and region B of low density polyethylene.
• Moreover, any of a variety of different polymeric materials known by those of skill in the art to be suitable for catheter body manufacture may be used to form[0108]tubular body16. For example,tubular body16 may be formed out of Pebax™, blends of Pebax™, and nylons, polyetheretherketone (PEEK), polyethylenes, and Hytrel™, and the like. Different materials might also be combined or blended to select for desirable flexibility properties.
• Also, although[0109]tubular body16 has been described in the context of having two regions of differing flexibility, it will be readily appreciated by those of skill in the art that three or more regions of differing flexibility may easily be provided, by adapting the teachings contained herein.
• In the above-discussed embodiments, and all other embodiments of the present invention, it may be preferred to provide[0110]main lumen30 and the outer surface oftubular body16 with a hydrophillic coating, a hydrophobic coating, or combinations thereof. For example,main lumen30 may be provided with a hydrophobic coating, such as silicone, whiletubular body16 is provided with a hydrophillic coating, such as polyvinyl pyrrolidone (PVP), polyurethane blends, copolymers of acrylonitrile, and the like. Other hydrophobic and hydrophillic coatings, as known to those of skill in the art, may also be used. In addition, any of a variety of antithrombogenic coatings, such as heparin, may also be applied to the catheter of the present invention, alone or in combination with other coating types.
• Referring to FIGS. 4 and 5, there is illustrated a cross-sectional view of the[0111]distal end14 ofcatheter10.Distal end14 is provided with a softdistal tip50, which is not preformed withtubular body16, but is instead attached totubular body16 as a tube post manufacturing step.Distal tip50 is preferably soft enough and flexible enough, so as to minimize trauma to body vessels ascatheter10 is advanced, and also to facilitate navigation ofcatheter10 in tortuous vessels. In one preferred embodiment,distal tip50 is formed as a 0.5 cm sleeve of 25-40D Pebax™, and is bonded totubular body16 by heat fusing. Alternately,distal tip50 may be attached totubular body16 by adhesives, or by insert molding, as is known to those of skill in the art. Preferably,distal tip50 is in alignment withtubular body16, and does not bend or curve, such that the radial axis ofdistal tip50 is substantially the same as that oftubular body16.
• The[0112]distal end14 ofcatheter10 is also preferably provided with a radiopaque material44. Advantageously, radiopaque material44 serves as a marker to help theclinician position catheter10 during a medical procedure. Various well-known radiopaque materials may be used indistal end14, such as platinum, gold, and platinum-iridium blends. The full length, or part of the length of the tubular body, may also be radiopaque by blending radiopaque materials in the polymeric materials used to form the body. Furthermore, radiopacity of the tip can also be achieved by loading (i.e., comparing) thedistal tip50 with a sufficient amount of barium sulfate. Alternatively, bismuth subcarbonate, bismuth trioxide or bismuth oxychloride may be used as a radiopaque filler. Also, radiopacity may be achieved by using radiopaque wire or flat ribbon to make the braid or coil.
• Illustrated in FIGS.[0113]6-9, there is an emboli containmentsystem utilizing catheter10 of the present invention.Catheter10 of the present invention is used in the treatment of astenosis55 in alumen50 in a blood-carryingvessel58 in which thestenosis55 at least partially occludes thelumen50. The emboli containment system depicted in FIG. 6 comprises acatheter10, as described above, as well ascatheters100 and200.
• [0114]Catheter100 comprises an elongate flexibletubular body116 having proximal end anddistal end114. Aninflatable balloon126 of the same type asinflatable balloon26 is coaxially mounted ontubular body116 on theend114 ofcatheter100. Thetubular body116 has centrally disposedinflation lumen132 in fluid communication withballoon126, such that fluid passing throughlumen132 may be used to inflateballoon126. Alternatively, fluid may be withdrawn fromlumen132 to deflateballoon126. As shown in FIG. 6,catheter100 is disposed withinmain lumen30 ofcatheter10 and is slidably and coaxially mounted therein for variable displacement ofballoon126 with respect to thefirst balloon26, as hereinafter described. One preferred embodiment of acatheter100 is disclosed in our co-pending application, entitled HOLLOW MEDICAL WIRES AND METHODS OF CONSTRUCTING SAME, Ser. No. 08/812,876, filed Mar. 6, 1997, now U.S. Pat. No. 6,068,623, the entirety of which is incorporated by reference.
• The emboli containment system also comprises[0115]catheter200 comprising an elongate flexibletubular body216 having proximal end anddistal end214.Catheter200 is also provided with a generally centrally disposedlumen230 extending from the proximal end to the distal end ofcatheter200, and through whichcatheter100 is coaxially and slidably mounted.
• The[0116]distal end214 ofcatheter200 is provided with means for performing a medical procedure, such as an apparatus for treatingstenotic lesion55. In the embodiment of the invention shown in FIG. 6, this means comprises adilatation balloon226, which is preferably a non-compliant inflatable balloon which is coaxially mounted on thedistal end214 ofcatheter200.Balloon226 may also be attached totubular body216 in the same manner as balloons26 and126 hereinbefore described.Tubular body216 is provided with aballoon inflation lumen232 which is in fluid communication withballoon226, such thatballoon226 may be inflated by the passage of fluid throughlumen232.
• The operation and use of the emboli containment system utilizing the catheter of the present invention for treating occluded vessels may now be briefly described in connection with an occlusion formed by a stenosis in a carotid artery, as illustrated in FIGS.[0117]10A-E.
• [0118]Catheter100 is inserted into an incision into a femoral artery of a patient and is advanced through that artery into the aorta of the patient and into the ostium of the carotid artery to be treated. Aftercatheter100 has been introduced,catheters10 and200, withballoons26 and226 completely deflated, are introduced overcatheter100 and are advanced into the ostium of the carotid artery and into the lumen or passageway of the vessel as shown in FIGS.10A-E.
• The emboli containment system is advanced until[0119]catheter10 is proximal of astenosis55 in thevessel lumen50 to be treated.Balloon26 is then inflated by introducing a suitable inflation medium such as a radiopaque liquid intoport18 to cause it to pass through theballoon inflation lumen32 to inflateballoon26, as shown in FIG. 10B.Balloon26 is progressively inflated until it engages theside wall58 of the vessel to occlude thelumen50.
• [0120]Catheter100 is then advanced throughstenosis55 as shown in FIG. 10C.Catheter100 with deflatedballoon126 thereon is advanced throughstenosis55 until theballoon26 is distal ofstenosis55 as shown in FIG. 10D.Balloon126 is then inflated by passing an inflation medium throughlumen132 to the interior of theballoon126 to inflate theballoon126 until it engages thesidewall58 of thevessel lumen50. As soon as theballoon126 has been inflated, a working space is provided betweenballoons26 and126, so that medical procedures can be undertaken to remove or reduce thestenosis55 in the space betweensecond balloons26 and126, without risk of unwanted particles or emboli escaping into the blood stream.
• For emboli containment systems featuring balloon dilatation treatment, it is desired to compress the plaque or material forming the stenosis to provide a larger vessel. Thus,[0121]catheter200 is advanced overcatheter100 to causedistal end214 withballoon226 thereon to be advanced into the working space. As soon asballoon226 has been properly positioned withinstenosis55,balloon226 is inflated with a suitable inflation medium, as for example a radiopaque liquid.Balloon226 can be inflated to the desired pressure to cause compression of the plaque of thestenosis55 against thesidewall58 oflumen50 by the application of appropriate inflation pressure. As in conventional angioplasty procedures,balloon226 can be formed of a non-elastic relatively non-compliant material so that appropriate pressures, such as 10-15 atmospheres, can be used withinballoon226 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.
• Once the clinician is satisfied that the[0122]occlusion forming stenosis55 has been sufficiently compressed,balloon226 can be deflated. After the appropriate dilation ofstenosis55 has been accomplished,catheter200 can be removed from the stenosis. Moreover, in one preferred method,catheter200 is completely withdrawn from the emboli containment system, and an irrigation catheter is inserted overcatheter100 and throughlumen30, as described in our copending application entitled METHOD FOR EMBOLI CONTAINMENT, Ser. No. 08/812,875, filed Mar. 6, 1997, now U.S. Pat. No. 5,833,644, the entirety of which is incorporated by reference. Fluid introduced into the working space may be removed by supplying a negative pressure or suction toaspiration port20. This creates a negative pressure within space30adefined by the interior surface oflumen30 and outertubular body216, to suck or aspirate blood or other fluids inlumen50 into space30aand out ofaspiration port20. In this manner, irrigation and aspiration of the working space may take place so that any plaque coming off the occlusion forming thestenosis55 can be aspirated out of the vessel. Subsequently,balloon26 andballoon126 can be deflated to permit normal blood flow through thevessel lumen50. The entire catheter assembly can then be removed and a suture applied to the incision created to obtain access to the femoral artery.
• 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.[0123]
• 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.[0124]
• More particularly as shown in FIGS.[0125]11-14, thecatheter apparatus311 of the present invention is for use in the treatment of astenosis312 in alumen313 in a blood-carrying vessel314 in which thestenosis312 has a length and a width or thickness which at least partially occludes thelumen313. The apparatus consists of a first elongate flexibletubular member316 formed of a suitable plastic material which is provided with proximal anddistal extremities317 and318. Afirst balloon319 is mounted on thedistal extremity318 and preferably is a compliant balloon formed of a suitable elastic material such as a latex or a very low radiation polyethylene so that it can be inflated to the size of the vessel314 in which it is to be disposed. Thus, theballoon319 should be capable of expanding to various diameters depending on the size of the vessel. Thefirst balloon319 can be formed as a separate balloon separate from the elongatetubular member316 as shown and adhered thereto by suitable means such as an adhesive (not shown), or it can be formed integral with thetubular member16 in a manner well known to those skilled in the art.
• The[0126]tubular member316 is provided with a large centrally disposed ormain lumen321 extending from theproximal extremity317 to thedistal extremity318. It is also provided with aballoon inflation lumen322 which has a distal extremity in communication with the interior of thefirst balloon319 through aport323. The proximal extremity of theballoon inflation lumen322 is in communication with a balloon inflation fitting324 mounted on theproximal extremity317 of thetubular member316. The fitting324 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 thefirst balloon319.
• The first[0127]tubular member316 is also provided with anaspiration lumen326 which exits through thedistal extremity318 and theproximal extremity317 of thetubular member316. A Luer-type fitting327 is mounted on theproximal extremity317 and is in communication with theaspiration lumen326. The fitting327 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[0128]apparatus311 also consists of a second elongate flexibletubular member331 having proximal anddistal extremities332 and333. A secondinflatable balloon336 of the same type as the first inflatable balloon is coaxially mounted on thedistal extremity333 in a conventional manner. Thetubular member331 is provided with a large generally centrally disposed arterialblood flow lumen337 which opens through thedistal extremity333 and is in communication with a Luer-type fitting338 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[0129]tubular member331 is also provided with aballoon inflation lumen339 which is in communication with the interior of the secondinflatable balloon336 through aport341. The proximal extremity of thelumen339 is in communication with the Luer-type fitting342 mounted on theproximal extremity332 of the secondtubular member31 and as with the balloon inflation fitting324 is adapted to be connected to a balloon inflation-deflation device (not shown) of a conventional type. The secondtubular member331 is also provided with alumen343 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. Thelumen343 is sized so that it is adapted to receive aconventional guide wire346 as for example a 0.014″ or 0.018″ guide wire and extends from the proximal extremity to the distal extremity so that theguide wire346 can extend beyond the distal extremity of the secondtubular member331. A fitting347 is provided on theproximal extremity332 in communication with thelumen343 for introducing the saline solution.
• As shown in FIG. 11, the second[0130]tubular member331 is disposed within thecentral lumen321 of the firsttubular member316 and is slidably and coaxially mounted therein for displacement of thesecond balloon336 with respect to thefirst balloon319 as hereinafter described.
• The catheter assembly or[0131]apparatus311 also consists of a third elongate flexibletubular member351 having proximal anddistal extremities352 and353. It is provided with a centrally disposedlumen356 extending from theproximal extremity352 to thedistal extremity353 and through which the secondtubular member331 is coaxially and slidably mounted.
• [0132]Means357 is provided on thedistal extremity353 of the thirdtubular member351 for performing a medical procedure. In the embodiment of the invention shown in FIG. 11, this means357 consists of athird balloon358 which can be non-compliant coaxially mounted on the distal extremity of the thirdtubular member351. Thethird balloon358 can be attached in the same manner as the first andsecond balloons319 and336 hereinbefore described. The thirdtubular member351 is provided with aballoon inflation lumen359 which has its distal extremity in communication with the interior of theballoon358 through aport361. The proximal extremity of theballoon inflation359 is in communication with a Luer-type fitting362 provided on theproximal extremity352 and adapted to be connected to a conventional inflation deflation device (not shown) for inflating and deflating thethird balloon358.
• The operation and use of the catheter assembly or[0133]apparatus311 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 FIGS. 15 and 16A-16E. A guiding catheter363 (FIG. 15) of a conventional type is inserted into an incision into afemoral artery364 of a patient and is advanced through that artery into the aorta of theheart365 of the patient and into theostium366 of the selected carotid artery or vessel as for example theleft carotid367.
• After the guiding catheter has been appropriately positioned, the[0134]guide wire346 is introduced separately into the guiding catheter or along with thecatheter assembly311. The distal extremity of the catheter apparatus orassembly311 with all of the first, second andthird balloons319,336 and358 completely deflated, is introduced into the guidingcatheter363 along with or over theguide wire346 and is advanced through the guidingcatheter363 into theostium366 of the carotid artery orvessel367 and into the lumen orpassageway368 of the vessel as shown in FIGS. 15 and 16B.
• The distal extremity of the[0135]catheter assembly311 is advanced until it is just proximal of astenosis369 in thecarotid artery367 to be treated. Theballoon319 is then inflated by introducing a suitable inflation medium such as a radiopaque liquid into the fitting324 to cause it to pass through theballoon inflation lumen322 through theport323 and into the interior of thefirst balloon319 to inflate the same as shown in FIG. 16B. Theballoon319 is progressively inflated until it engages the side wall of thevessel367 to occlude thevessel367. At the time that this is occurring, a negative pressure or suction is applied to the aspiration fitting327 to supply a negative pressure through theballoon inflation lumen322 to suck or aspirate blood in thevessel367 distal of thefirst balloon319 into theaspiration lumen326 and out the aspiration fitting327 to thereby reverse the flow of blood through the stenosis as shown by thearrows371 in FIG. 16B.
• While a reverse flow of blood is occurring in the[0136]vessel367, theguide wire346 is advanced through thestenosis369 as shown in FIG. 16C. In the event that any pieces or particles of plaque are knocked off of the occlusion formed by thestenosis369 by movement of theguide wire346 through the same, such pieces of plaque or emboli will be drawn out with the reverse flow of blood into theaspiration lumen326 and out of the aspiration fitting327. During the time that theguide wire346 is being advanced through thestenosis369 it may be desirable at the same time to introduce a saline solution through theguide wire lumen343 of the second elongate flexibletubular member331 to exit through the distal extremity of the second elongate flexibletubular member331 into the space immediately proximal of thestenosis369. This introduced saline solution aids the flow of particulate or other particles dislodged from thestenosis369 during advancement of theguide wire346 through the same and carries them back with the mixed saline blood solution through theaspiration lumen326 in a manner hereinbefore described.
• With the[0137]guide wire346 remaining in position, the second elongate flexibletubular member331 with thesecond balloon336 thereon in a deflated condition is advanced over theguide wire346 through thestenosis369 until thesecond balloon336 is distal of thestenosis369 as shown in FIG. 16D after which thesecond balloon336 is inflated by introducing an inflation medium as for example a radiopaque liquid through the inflation fitting342 into thelumen339 through theport341 to the interior of thesecond balloon336 to inflate thesecond balloon336 until it engages the sidewall of thevessel367.
• Prior to, during or after inflation of the[0138]second balloon336, theguide wire346 can be removed. However, it is preferable to remove theguide wire346 as soon as thesecond balloon336 has been advanced so that it is beyond thestenosis369. At this time, and certainly prior to complete inflation of thesecond balloon336, blood is shunted across thestenosis369 and into thelumen368 distal of thesecond balloon336 by introducing blood through the fitting338 and into the centrally disposedblood flow lumen337 in the secondtubular member331 so that it exits out thecentral lumen337 distal of thesecond balloon336. The blood which is supplied to the fitting337 can be taken from another femoral artery of the patient and pumped into the fitting338. In addition, if desired, the blood which is aspirated in the space distal of thefirst balloon319 can be appropriately filtered and also supplied to the fitting338. By shunting blood past thestenosis369 in this manner it can be seen that blood is being continuously supplied to the carotid artery of the patient during the time that thesecond balloon336 is inflated and occludes thelumen368 in thevessel367.
• As soon as the[0139]second balloon336 has been inflated, it can be seen that there is provided a working space376 (FIG. 16D) between the first andsecond balloons319 and336 so that medical procedures can be undertaken to remove or reduce thestenosis369 in the space between the first andsecond balloons319 and336.
• Assuming that it is desired to compress the plaque or material forming the[0140]stenosis369 to provide a larger lumen, opening or passageway through thestenosis369 the thirdtubular member51 can be advanced by grasping theproximal extremity352 to cause the distal extremity with thethird balloon358 thereon to be advanced into the workingspace376. As soon as theballoon358 has been properly positioned within thestenosis369, theballoon358 also can be inflated with a suitable inflation medium as for example a radiopaque liquid. Theballoon358 can be inflated to the desired pressure to cause compression of the plaque of the occlusion against the sidewall of thevessel367 by the application of appropriate pressure. As in conventional angioplasty procedures, thethird balloon358 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[0141]vessel367 by the shunt hereinbefore described, the compression of the occlusion forming thestenosis369 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 thestenosis369 as shown in FIG. 16E. If it is believed that the occlusion forming thestenosis369 has been sufficiently compressed, thethird balloon358 can be deflated. In the event an inelastic balloon is utilized for thethird balloon358, and it is desired to utilize a larger third balloon, this can be accomplished by removing the thirdtubular member351 with the deflatedballoon358 thereon and introducing a thirdtubular member351 having a larger size balloon thereon over the secondtubular member331 and advancing it into thestenosis369 and inflating the larger size balloon to create a still larger passage through thestenosis369.
• After the appropriate dilation the[0142]stenosis369 has been accomplished the third balloon can be removed from the stenosis while aspiration of the workingspace376 is still ongoing so that any plaque coming off the occlusion forming thestenosis369 can be aspirated out of the vessel. After thethird balloon358 has been removed from the stenosis, thesecond balloon336 and thefirst balloon319 can be deflated to permit normal blood flow through thevessel367 after which the arterial blood flow supply to the fitting338 can be terminated. Theentire catheter assembly311 can then be removed from the guidingcatheter363 after which the guidingcatheter363 can be removed and a suture applied to the incision created to obtain access to the femoral artery.
• In place of the[0143]third balloon358 for causing compression of the occlusion forming thestenosis367 to create a larger passageway therethrough, an atherectomy device381 (see FIG. 17) can be utilized for operating in the workingspace376 to remove the plaque of the occlusion forming the stenosis. This can be accomplished with a catheter assembly orapparatus381 which in many respects is similar to theapparatus311 shown in FIG. 11 and consists of a firsttubular member316 with afirst balloon319 and a second tubular331 with asecond balloon336 thereon. In place of the third flexible elongatetubular member351 there is provided a third flexible elongatetubular member386 which is provided with proximal anddistal extremities387 and388. The flexible elongatetubular member386 is slidably and rotatably mounted in thecentral lumen321 of the flexibleelongate member316 and is provided with a central or main lumen389 through which the second flexible elongatetubular member331 extends. It is also provided with a lumen391 extending from the proximal extremity to the distal extremity through which a saline solution can be introduced for saline irrigation as hereinafter described. It is also provided with anotherlumen392 which is adapted to receive a plurality of electrical conductors393 for performing electrical functions as hereinafter described. Thelumen392 is connected to a conventional Luer-type fitting396 serving as a fluid irrigation fitting mounted on the proximal extremity firsttubular member312 and is in communication with an annular recess397 which is in communication with the lumen391 provided in thetubular member386 for supplying a saline irrigation liquid through the flexible elongatetubular member386 and into the workingspace376 provided between the first andsecond balloons316 and336. In order to aid aspiration of the saline irrigation liquid from the workingspace376, the outer surface of the flexible elongatetubular member386 is provided with ahelical groove398 therein which has one end which opens into the workingspace376 and which has the other end in communication with the aspiration fitting327.
• Means is provided for rotating the second[0144]tubular member386 and consists of suitable means such as aspur gear401 mounted on the proximal extremity387 of thetubular member386. Thespur gear401 is driven in a suitable manner as for example by anothersmaller spur gear402 which is of greater width thanspur gear401 so as to provide a splined gear connection between thegears401 and402. This accommodates the desired longitudinal movement for thetubular member386 so that thedistal extremity388 of thetubular member386 can be advanced and retracted in the workingspace376 as hereinbefore described. Anelectrical drive motor403 is provided for driving thegear402.
• Atherectomy means[0145]406 is provided on thedistal extremity388 of the flexible elongatetubular member386. As shown in FIGS. 17 and 19, the atherectomy means406 consists of a flexibleelongate member407 formed of a suitable material such as stainless steel or preferably a superelastic Nitinol. The flexibleelongate member407 is wound into a helix as shown in FIG. 19 onto the distal extremity of thetubular member386. The flexibleelongate member407 can be formed of a ribbon having a thickness of 0.003″ and a width of 0.060″. One end of the flexibleelongate member407 can be secured to thetubular member386, as for example by inserting the same into aslit408 and additionally by the use of adhesive (not shown). The flexibleelongate member407 is wrapped into a helix in a direction opposite to the direction of normal rotation of thetubular member386 and can be provided with aspecial tip409 on its free end with the tip having anarcuate surface411 that is inclined rearwardly to terminate at a cutting edge412 (see FIG. 19) which is adapted to engage the plaque or thestenosis369.
• When the[0146]distal extremity388 of the flexible elongatetubular member386 has been introduced into the workingspace376, the end or tip409 of the flexibleelongate member407 of the atherectomy means406 is free. A saline solution is introduced into the fitting357. Thereafter themotor403 can be energized to cause rotation of thetubular member386 and to thereby cause rotation of the helically wound flexibleelongate member407 to cause its free end ortip409 to be moved outwardly radially under centrifugal force to bring thecutting edge412 into engagement with theplaque369 in thestenosis369 to cause progressive removal of the plaque forming thestenosis369 to enlarge the passageway extending through the stenosis. Because of the rounded configuration of thetip409, thetip409 will not dig into the vessel wall but will only remove plaque which is engaged by thecutting edge412. As the plaque is being removed, the saline solution introduced through the fitting396 into thespace376 picks up the plaque particles or emboli as they are being removed. The saline solution with the plaque or emboli therein is removed through thespiral groove398 and through theaspiration port327. The flexible elongatetubular member386 can be moved back and forth so that thecutting tip409 engages the length of thestenosis369 so that substantially all of thestenosis369 can be removed.
• Means is provided to sense when sufficient plaque has been removed from the[0147]stenosis369 and to ensure that cuttingedge412 does not cut into the vessel wall. An ultrasonic sensor416 (see FIG. 17) is mounted in the distal extremity of thetubular member386 and is connected by conductors393 (see FIG. 18) extending through thelumen392 and connected to acable418 which is connected to anultrasonic power supply419 and avideo monitor421. By using the Doppler effect, ultrasonic energy can be utilized in connection with the transducer416 to ascertain the depth of cut being made by the flexibleelongate member407 as it is being rotated.
• As soon as a desired amount of plaque has been removed from the[0148]stenosis369 to provide the desired passage through the stenosis, rotation of thetubular member386 is terminated after which thetubular member386 can be withdrawn followed by deflation of thesecond balloon336 and withdrawing it. Deflation of thefirst balloon316 then occurs after which it is withdrawn from thevessel367. Thereafter, the guidingcatheter363 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[0149]cylindrical stent426 in thestenosis369. Such astent426 can be a self-expanding stent formed of a suitable material such as a superelastic Nitinol and movable between unexpanded and expanded conditions. Such astent426 can be placed by asuitable catheter apparatus431 of the type shown in FIG. 20. Thestent426 which is cylindrical in form is pushed over the proximal extremity of the second elongate flexibletubular member331 into the main orcentral lumen321 so that it is retained in the unexpanded position. It is then pushed forwardly toward the distal extremity of the first flexible elongatetubular member316 by means of a flexible elongatetubular member436 having proximal anddistal extremities437 and438 and having aflow passage439 extending from theproximal extremity437 to thedistal extremity438. Theproximal extremity437 is provided with aknurled collar441 which is adapted to be engaged by the hand to facilitate pushing of the flexible elongatetubular member436 so that its distal extremity is in engagement with thestent426. Thus, when desired thestent426 may be discharged or dislodged from the distal extremity of the secondtubular member331 and pushed into the workingspace376 created between thefirst balloon319 and thesecond balloon336.
• After the[0150]stent426 has been discharged out of the end of the first flexible elongatetubular member316, thestent426 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 thestenosis369 to frictionally retain the stent in engagement with the vessel wall. As soon as thestent426 is in engagement with the vessel wall, thesecond balloon336 can be deflated as can thefirst balloon319. The first deflatedballoon336 can then be withdrawn through the interior of thecylindrical stent426. This can be followed by deflation of thefirst balloon319 and the removal of the flexible elongatetubular member316 with itsfirst balloon319 and the flexibletubular member331 with itssecond balloon336, along with the flexibleelongate member436 until the entire catheter assembly orapparatus431 has been removed from the guidingcatheter363. Thereafter the guidingcatheter363 can be removed and the incision sutured as hereinbefore described.
• In FIG. 21, there is shown another embodiment of an apparatus[0151]451 incorporating the present invention which is particularly adapted for use treating a stenosis at or near a bifurcation appearing in an arterial vessel. The apparatus451 is shown being used on ahuman being452 showing the principal arteries and pulmonary veins of the human body. Thus there as shown, theabdominal aorta453 branches into thecommon iliac454 which branches into the external iliac456 and theinternal iliac457. The external iliac branches into the deepfemoral artery458 and into thefemoral artery459. Theabdominal aorta453 extending in the opposite direction passes through theaortic arch461 of theheart462. Theaortic arch461 is connected to thecommon carotid466 which extends into abifurcation467 branching into theexternal carotid468 and theinternal carotid469. Similar bifurcations appear in the basilar artery which is an artery which is particularly inaccessible for surgical treatment.
• As hereinafter explained, the apparatus[0152]451 shown in FIGS. 21, 22 and23 consists of a proximalocclusion balloon catheter476 which can be considered to be a first catheter. Thecatheter476 is formed of a flexible elongatetubular member477 having proximal anddistal extremities478 and479. Thetubular member477 is formed of a suitable material such as plastic and can have a suitable size ranging from 5 to 14 French and preferably 9 to 10 French. Aballoon481 is provided on thedistal extremity479 and is formed of a suitable elastic material. It is generally cylindrical in form and has its proximal and distal extremities secured to thetubular member477 by suitable means such as an adhesive (not shown). Thetubular member477 is provided with a plurality of lumens therein. Onelumen482 serves as a balloon inflation lumen and extends from theproximal extremity478. It can have a suitable size such as 0.024″ and hasport483 in communication with the interior of theballoon481. A manifold486 formed of a suitable material such as plastic is mounted on theproximal extremity478. Atubular member487 is mounted in the manifold486 and is in communication with theinflation lumen482.
• The[0153]tubular member477 is also provided with alarge lumen491 having a suitable size as for example 0.045″ which is adapted to slidably receive therein atherapeutic balloon catheter492 and aperfusion balloon catheter493. It is also provided with anotherlumen496 having a suitable size as for example 0.026″ which is adapted to receive a balloon-on-a-wire catheter497. It is also provided with anaspiration lumen501 having a suitable size as for example 0.025″ and anirrigation lumen502 having a suitable size as for example 0.015″. There is also provided anotherlumen503 which can be used for other purposes.
• The[0154]therapeutic balloon catheter492 and theperfusion balloon catheter493 are constructed in a manner similar to the balloon catheters hereinbefore described. Thus theperfusion balloon catheter493 is provided with a flexible elongatetubular member506 having proximal anddistal extremities507 and508. Aballoon509 formed of an elastic material is secured to thedistal extremity508 by suitable means such as an adhesive (not shown) and is adapted to be inflated through a port510 in communication with aballoon inflation lumen511. Thetubular member506 is also provided with ablood perfusion lumen512 which is centrally disposed therein. Theproximal extremity507 of thetubular member506 is connected to a Y adapter or fitting513 of which thecentral arm514 is in communication with theblood perfusion lumen512 and is provided with a Luer-type fitting516. Theside arm517 of the fitting513 is in communication with theballoon inflation lumen511 and is provided with a Luer-type fitting518 adapted to be connected to a source of pressure as hereinafter described.
• The[0155]therapeutic balloon catheter492 consists of atubular member521 having a proximal anddistal extremities522 and523. Aballoon524 formed of a non-elastic material is secured to thedistal extremity523 by suitable means such as an adhesive. A port (not shown) is in communication with the interior of theballoon524 and is in communication with aballoon inflation lumen526. A Luer-type fitting527 is mounted on theproximal extremity522 and is in communication with theballoon inflation lumen526. Another fitting528 is mounted on theproximal extremity522 and is in communication with a large centrally disposed lumen529 which can receive theperfusion balloon catheter493 for slidable movement as hereinafter described.
• The balloon-on-[0156]a-wire catheter497 is slidably mounted in thelumen496 and consists of aguide wire531 of a conventional construction having a suitable diameter as for example 0.018″ and having a proximal anddistal extremities532 and533. Aballoon534 formed of a non-elastic material is mounted on the distal extremity533 and is secured thereto by suitable means such as an adhesive (not shown). The proximal extremity of theballoon534 is secured to the distal extremity of atubular member536 formed of a suitable material such as plastic and which is coaxially disposed on theguide wire531. Thetubular member536 extends the length of the guide wire to the proximal extremity and is connected to a Luer-type wye fitting537 and is in communication with anannular lumen538 disposed between thetubular member536 and the exterior surface of theguide wire531. Thelumen538 is in communication with the interior of theballoon534 for inflating and deflating theballoon534. The balloon-on-a-wire catheter497 is adapted to be introduced through a fitting541 carried by atube542 mounted in the manifold486 and in communication with thelumen496 in the multi-lumen elongatetubular member477.
• A[0157]tube546 is mounted in the manifold486 and is in communication with thelarge lumen491 and is provided with a fitting547 which is adapted to receive theperfusion balloon catheter493 and thetherapeutic balloon catheter492 as hereinafter described. Another tube551 is provided in the manifold486 and is in communication with theaspiration lumen501. It is provided with the fitting552. Another tube fitting553 is mounted in the manifold486 and is in communication with theirrigation lumen502 and is provided with a fitting554.
• The various fittings for the catheter as hereinbefore described are adapted to be connected into a control console[0158]571. The control console571 consists of arectangular case572 which is provided with afront panel573.
• A plurality of balloon[0159]inflation deflation devices576 of a conventional type typically called endoflaters are mounted within thecase572 and have control handles577 extending through vertically disposed slots578 provided in the front panel. Theseendoflaters576 are labeled as shown in FIG. 21 and are connected by tubing (not shown) through pressure gauges581 mounted in thefront panel573 and are provided withneedle indicators582 to indicate the pressure being applied by the endoflater to the tubing. The tubing is connected in such a manner so that theendoflater576 and the associated pressure gauge581 are connected to atube586 which is provided with a mating fitting587 adapted to mate with a fitting488 so that it is in communication with theinflation lumen482 of the proximalocclusion balloon catheter476. In a similar manner, thetubing588 is provided with a fitting589 which mates with a fitting518 of theballoon inflation lumen511 of theperfusion balloon catheter493 for inflatingballoon509. Similarly,tube591 with itsmating fitting592 is adapted to mate with the fitting537 for inflating theballoon534. Similarly, thetube593 with its fitting594 mates with the fitting527 in communication with theballoon inflation lumen526 for inflating theballoon524 of thetherapeutic catheter492. Anothertube596 which is provided with its fitting597 mates with the fitting552 that is in communication with theaspiration lumen501. Thetube596 is in communication with the inlet of ablood pump601 of a suitable type as for example a roller pump well known to those skilled in the art which is mounted within thecase572 and which is connected to a source of electrical power throughelectrical plug602 connected into thecase572. Theroller pump601 is provided with an on/offswitch603 mounted on thefront panel573. After it passes through thepump601, blood is supplied to a blood filter606 of a conventional type and then is supplied through atube611 having a fitting612 adapted to mate with the fitting516 of the perfusion balloon catheter which is in communication with theperfusion lumen512.
• A three-[0160]way valve616 is associated with each of theendoflaters576 and has acontrol knob617 extending through thefront panel573 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 FIG. 24.
• Operation and use of the apparatus[0161]451 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 FIGS. 25A through 25D. As shown in the illustration in FIG. 25A, let it be assumed that a stenosis is present adjacent thebifurcation467 and in theexternal carotid468 and that it is desired to treat this stenosis in accordance with the apparatus451 of the present invention in performing the method of the present invention. The proximalocclusion balloon catheter476 is loaded with thetherapeutic balloon catheter492 slidably mounted over theperfusion balloon catheter493 and both are slidably mounted in themain lumen491. The balloon-on-a-wire catheter497 is slidably mounted in the lumen. While the patient is being prepared for the procedure, all of the lumens in the catheters of the apparatus are flushed with saline to remove all air from the lumens. They are then connected to the control console571 in the manner hereinbefore described and as shown in FIG. 21. An incision626 (see FIG. 21A) is made in the femoral artery in the left leg of the patient and a guiding catheter (not shown) similar to the type utilized in angioplasty is introduced through thefemoral artery459. This guiding catheter is advanced until it is near theaorta arch461. Thereafter, the first or proximalocclusion balloon catheter476 has itsdistal extremity479 introduced into the guiding catheter and advanced in the guiding catheter. It is advanced so that itsdistal extremity479 enters the common carotid and is near thebifurcation467. Theballoon481 is inflated by operating the control handle577 associated with theproximal occlusion balloon481 as shown in FIG. 25A to create the desired pressure within and to inflate theelastic balloon481 so that it occludes the common carotid just proximal of the stenosis624. As soon as this occurs, theroller pump601 is turned on by operating the on/offswitch603 to create a negative pressure on the distal side of theballoon481 to cause blood to flow in a reverse direction as shown byarrows627 to thereby change the directional flow of blood from the internal and external carotids away from the brain rather than to the brain. The blood travels into theaspiration lumen501 as indicated by thearrows627 and into the tube551 throughfittings552 and597 andtube596 to theroller pump603. The blood after passing through theroller pump603 passes through a blood filter606 and then passes into thetube611 and the fitting612 and connected to the fitting589 of theperfusion catheter493. Alternatively, the fitting612 can be which is connected to another fitting631 mounted on a tube632 introduced into the venous side of the circulatory system of the patient's body, as for example into the vein in the right leg of thepatient452 as shown in FIG. 21. Any debris or emboli in the aspirated blood being pumped will be filtered out by the blood filter606.
• As soon as or during the time this retrograde circulation of blood is established through the[0162]roller pump601, theperfusion balloon catheter493 extending proximally from the fitting547 is advanced into theinternal carotid469 past thestenosis621 at thebifurcation467. If necessary, a guide wire can be utilized which can be introduced through theperfusion lumen512 to aide in advancing theperfusion balloon catheter493 into theinternal carotid469. Any emboli or debris dislodged from thestenosis621 by crossing the same either by the guide wire or by the distal extremity of thecatheter493 will be picked up by the retrograde flow of blood which is being aspirated through the proximalocclusion balloon catheter476 to thereby prevent any emboli or debris from entering the brain of the patient. Theelastic perfusion balloon509 is then inflated as shown in FIG. 25B using the appropriate endoflater to inflate the balloon to the desired pressure while watching the associated pressure gauge. As soon as occlusion occurs, perfusion of blood can be started as hereinafter described.
• Prior to or after the[0163]balloon509 ofperfusion catheter493 has been inflated, the balloon-on-a-wire catheter497 extending proximally of the fitting541 is advanced into theexternal carotid469 as shown in FIG. 25C. Theballoon534 is then expanded by use of the appropriate endoflater to supply an inflating medium through the fitting537 to occlude theexternal carotid469. As soon as occlusion has been accomplished in both the external and internal carotids, retrograde flow of blood is terminated by shutting off theroller pump601. It should be appreciated that if desired, automatic controls can be provided whereby when a certain pressure is reached in each of theballoons509 and534 the roller pump would automatically be shut off to stop retrograde flow. By this procedure, it can be seen that the lesion ofstenosis621 has been bracketed by theballoons481,509 and534. Prior to that occurring, retrograde flow of blood is established to prevent any emboli or debris from moving towards the brain.
• 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[0164]516 of theperfusion catheter506 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 theperfusion balloon509 as shown by thearrows628 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[0165]lumen469, theroller pump601 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[0166]stenosis621 has been bracketed as hereinbefore described and a workingspace636 formed adjacent the stenosis orlesion621, a therapeutic procedure can be employed. By way of example this can consist of advancing thetherapeutic balloon catheter492 over and axially of theperfusion catheter493 to bring itsballoon524 into registration with thestenosis621 as shown in FIG. 25D. Thereafter, theballoon524 can be inflated by use of the appropriate endoflater as hereinbefore described to cause the inelastic balloon to be pressurized to a pressure of 10 to 15 atmospheres to compress thestenosis621. Prior to or during this procedure it may be desirable to introduce a saline or heparin solution or a radiopaque contrast liquid into the workingspace636. This can be accomplished by introducing this liquid through theinjection lumen502. If desired, this can be accomplished prior to terminating the aspiration procedure hereinbefore described. Also it should be appreciated that if desired a small endoscope can be inserted through one of the lumens to view the area within the working space. Alternatively, if desired an ultrasonic probe can be utilized to view the area in which the lesion is disposed.
• 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.[0167]
• Let it be assumed that the desired therapeutic actions have been undertaken and that the[0168]stenosis621 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 catheter497 and theperfusion catheter493 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[0169]therapeutic balloon524 deflated. Theballoon534 of the balloon-on-a-wire catheter can be deflated as well as theperfusion balloon509. Perfusion of blood through the perfusion catheter can be terminated. Theperfusion balloon catheter493 and the balloon-on-a-wire catheter497 can be retracted into the main multi-lumentubular member477 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.[0170]
• 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.[0171]
• 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.[0172]
• 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.[0173]
• 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.[0174]
• With respect to an apparatus or assembly which does not require the use of perfusion, a[0175]main catheter651 utilized as a part of the apparatus is shown in FIGS. 26, 27,28 and29 consists of a flexible elongatetubular member652 formed of a suitable material such as plastic of the type hereinbefore described and which has proximal and distal extremities653 and654. The tubular flexible elongatetubular member652 can be of various sizes as for example for a saphenous vein graft catheter it can be 8 to 9.5 French in balloon profile with a length ranging from 80 cm to 120 cm. The flexible elongatetubular member652 can be formed of a suitable material such as PEBAX, Nylon, Hytrel, polyurethane or polyethylene. A flexible braid656 (see FIGS. 27, 28 and29) formed of a suitable material such as stainless steel is embedded within the wall of the flexible elongatetubular member652 as shown and extends from the proximal extremity653 to the distal extremity654. Thebraid656 can be formed of a suitable stainless steel such as a wire or ribbon having a thickness of 0.001″. Thebraid656 provides additional torquability and also inhibits the kinking of the flexible elongatetubular member652 when it must extend over a tight radius. The flexible elongatetubular member652 is provided with a largecentral lumen657 having a suitable diameter such as 0.065 or greater″ extending from the proximal extremity to the distal extremity.
• If it is desired to provide a flexible[0176]elongate member652 which has a greater flexibility at the distal extremity, a different material can be used in the distal extremity654. 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 flexibleelongate member652 having a Shore D hardness of 65-75.
• A supplemental flexible elongate[0177]tubular member661 is provided which has incorporated therein aballoon inflation lumen662. The supplemental flexible elongatetubular member661 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 elongatetubular member652 and overlies the outside wall of the flexible elongatetubular member652 and extends from the proximal extremity to near the distal extremity as shown in FIGS. 26 and 29. A tube663 of a suitable material such as Pebax extends over the length of thepolyimide tubing661 and is secured to the flexible elongatetubular member652 by ashrink tube666 extending from the proximal extremity653 to the distal extremity654, after which the shrink tube663 is subjected to heat. Theshrink tube666 is then subjected to a hot melt process of a temperature around 350° F. for a period of time until the Pebax tube663 melts, after which theshrink tubing666 can be stripped off so that there remains a relatively uniform mass formed of Pebax that surrounds thebraid657 and thepolyimide tube661 which forms the supplemental flexible elongatetubular member661. The polyimide tube which forms the supplemental flexible elongatetubular member661 thus provides an inflation lumen667 extending from the proximal extremity and to the distal extremity and opens through an opening668 into the interior of anocclusion balloon669 which is bonded to and coaxially mounted on the distal extremity of the flexibleelongate member652 in the manner shown in FIG. 29. The polyimide tubing is provided to give the ballooninflation lumen shaft361 greater strength than that which is provided by the Pebax itself.
• As can be seen from FIG. 29, the supplemental flexible elongate[0178]tubular member661 is terminated short of the distalmost extremity of the flexible elongatetubular member652 by approximately 1 cm. Theocclusion balloon669 is formed of various compliant or non-compliant materials. Suitable compliant materials include elastomers such as C-Flex latex, silicones and polyurethanes. Suitable non-compliant materials would be polyethylene, PET and Nylon. A composite material can also be used such as a combination of PET and an elastomer. Theocclusion balloon669 should have a strength so that it can readily accommodate any pressure of one atmosphere and as high as four atmospheres, or approximately 60 psi. Theocclusion balloon669 is cylindrical and is provided with proximal and distal extremities671 and672 which are secured by a suitable medical grade adhesive. Alternatively, fuse bonding may be used. Thus a seal673 formed of this adhesive bonds the proximal extremity671 of theocclusion balloon669 over the outer surface of the distal extremity of the flexible elongatetubular member652 and the supplemental flexible elongatetubular member661. Similarly, a seal674 bonds the distal extremity672 to the distal extremity of the flexible elongatetubular member652 to provide an air-tight space within the balloon accessible through the opening668. A softcylindrical tip676 formed of suitable material such as Pebax is bonded to the distal extremity of the flexible elongatetubular member652 and is provided with arounded surface677 which extends forwardly and has apassage678 therein in communication with thelumen657 and the flexible elongatetubular member652. A cylindricalradiopaque marker681 formed of a suitable material such as platinum, platinum-iridium or gold is mounted on the distal extremity of the flexible elongatetubular member652 in a position so it is substantially equidistant of the ends of theocclusion balloon669.
• A main adapter or fitting[0179]686 formed of a suitable material such as plastic is mounted on the proximal extremity653 of the flexible elongatetubular member652. It is provided with a first Luer fitting687 which provides aballoon inflation port688 in communication with theballoon inflation lumen662. It is also provided with another Luer fitting689 which is provided with anaspiration port691 in communication with the maincentral lumen657. Themain adapter686 is also provided with a Tuohy-Borst fitting692 which is in communication with thecentral lumen657. The Tuohy-Borst fitting692 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-ring693.
• A balloon-on-[0180]a-wire device701 incorporating the present invention is shown in FIGS. 30 and 31. Thedevice701 consists of aguide wire702 formed of a suitable material such as stainless steel and having a suitable diameter as for example ranging from 0.010″ to 0.032″ but preferably a diameter ranging from 0.014″ to 0.018″. It is preferable that theguide wire702 be formed of a nickel titanium alloy typically called Nitinol which has the advantage that it is more flexible and has greater kink resistance characteristics than another suitable material such as stainless steel.
• It has a suitable length as for example 150 cm. The[0181]guide wire702 is provided with proximal anddistal extremities703 and704 and is provided with acentral lumen706 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[0182]occlusion balloon711 is coaxially mounted on thedistal extremity704 of theguide wire702. Theocclusion balloon711 is preferably formed of the same material as theocclusion balloon669 on themain catheter651. Theocclusion balloon711 has proximal anddistal extremities712 and713. Atube716 formed of a suitable material such as a polyimide is disposed within theocclusion balloon711 and has abore717 extending therethrough which is sized so that it is slightly larger than the outside diameter of theguide wire702 so that its proximal extremity can be slipped over thedistal extremity704 of theguide wire702 and then bonded thereto by suitable means such as an adhesive718. A plurality of circumferentially spaced apart radially extendinginflation holes719 are provided in the proximal extremity of thetube716 and are in alignment with similarly spacedholes721 provided in thedistal extremity704 of theguide wire702 so that they are in communication with thecentral lumen706 of theguide wire702. The inflation holes719 as shown are in communication with the interior of theocclusion balloon711 so that fluid passing from thepassage706 can be utilized for inflating theocclusion balloon711.
• A[0183]solid core wire723 formed of a suitable material such as stainless steel is provided with a proximaltapered extremity724. Thecore wire723 is sized so it is adapted to fit within thelumen706 of theguide wire702 and is secured therein by suitable means such as an adhesive726 or alternatively a weld. Thecore wire723 has a taperedportion723awhich commences at theproximal extremity724 and which is tapered so that the cross-sectional diameter progressively decreases to the distal extremity of theocclusion balloon711. Thecore wire723 is also provided withadditional portions723band723cwhich can be of substantially constant diameter as for example 0.003″. Theportion723 is folded over with respect to theportion723bso that theportions723band723clie in a plane to facilitate shaping of the distal extremity of theguide wire702 during use of the same. Thecore wire723 is provided with a distal extremity727 in which abend728 is formed between the twoportions723band723c.Thebend728 is secured within a hemispherical solder bump orprotrusion729 which is carried by the distal extremity of acoil731 formed of a suitable radiopaque material such as platinum or a platinum alloy. Theplatinum coil731 can have a suitable outside diameter as for example 0.014″ corresponding to the diameter of theguide wire702 and can have a suitable length ranging from 1 to 3 cm. The proximal extremity of thecoil731 is secured to the distal extremity of thepolyimide tube716 by suitable means such as an adhesive732 which can be the same adhesive or adifferent adhesive733 utilized for securing thedistal extremity713 of the balloon to thepolyimide tube716 to form a fluid-tight seal between the distal extremity of theocclusion balloon711 and the distal extremity of thepolyimide716. From this construction it can be seen that theportions723band723cof thecore wire723 in addition to serving as a shaping ribbon are also utilized as a safety ribbon to ensure that thetip728 and thespring731 cannot be separated from theguide wire702. The proximal extremity712 of theballoon711 is also secured to the proximal extremity of thepolyimide tube716 and also to thedistal extremity704 of theguide wire702 to form a fluid-tight seal with respect to theocclusion balloon711 so that theocclusion balloon711 can be inflated and deflated through the inflation holes719 and721.
• Alternative constructions for the distal extremity of the[0184]core wire723 are shown in FIGS. 33 and 34. In FIG. 23 it can be seen that theportions723band723chave been twisted to in effect provide a twisted pair serving as a safety ribbon and as a shaping ribbon. In the embodiment shown in FIG. 34, thecore wire736 is provided with a tapered portion736awhich is the same as the tapered portions of723ahereinbefore described. However, thecore wire736 has been provided with adistal portion736bwhich has been flattened to a suitable thickness as for example a width of 0.006″ and a thickness of 0.003″ and then twisted to form a helix as shown in which the distal extremity is embedded within thesolder729. Such ahelix736 can serve as a safety ribbon and also can be shaped to some extent.
• A removable inflation fitting[0185]741 orvalve attachment741 is mounted on the proximal extremity of theguide wire702 and forms a part of the balloon-on-a-wire device701. The fitting orattachment741 is formed of a suitable material such as a polycarbonate and is provided with a central bore742. The attachment or fitting is slid externally over theproximal extremity703 of theguide wire702. Means is provided for forming a fluid-tight seal between theproximal extremity703 of theguide wire702 and abody743 of the fitting741 and consists of an o-ring746 (see FIG. 35) seated in awell747. Athumb screw748 is threadedly mounted on thebody743 and is provided with an inwardly extendingcircular protrusion749 that is adapted to engage the o-ring746 and to compress the same to form a fluid-tight seal when theprotrusion749 is moved inwardly toward the o-ring746 as thethumb screw748 is rotated in a clockwise direction. The o-ring746 decompresses or springs back when released upon rotation of thethumb screw748 in a counterclockwise direction so that the fitting741 can be removed from thedistal extremity703 of theguide wire702. The body742 also includes a Luer fitting751 which provides aninflation port752 that is in communication with the bore742 in thebody743 and which is also in communication with the open proximal extremity of theguide wire702 and thelumen706 therein.
• Means is provided for plugging the[0186]bore706 when the removable attachment or fitting741 is removed and consists of aplug mandrel756 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 thelumen706 and theguide wire702. Theplug mandrel756 is provided with aprogressive portion756athat tapers down from as, for example from 0.014″ to a suitable diameter as for example 0.008″ to acylindrical portion756b.
• Means is provided for forming a fluid-tight seal between the[0187]plug mandrel756 which forms a plug mandrel and thebody743 of the attachment or fitting741 and consists of an o-ring766 providing suitable sealing means seated within a well762 provided in thebody743. Athumb screw763 threadedly engages thebody743 and is provided with acylindrical protrusion764 which engages the o-ring and compresses it to form a fluid-tight seal with respect to theplug mandrel756 by rotation in a clockwise direction of thethumb screw763. Theplug mandrel756 can be released by a counterclockwise rotation of thethumb screw763 permitting decompression of the o-ring761.
• An[0188]irrigation catheter766 incorporating the present invention is shown in FIG. 36 and consists of a flexibleelongate tube767 formed of a suitable material such as polyethylene, PEBAX, Hytrel or Teflon having a suitable size as for example an outside diameter of 0.066″ and an inside diameter of 0.058″ and having a length of approximately 150 cm. A lumen768 is provided therein and extends from the proximal extremity to the distal extremity and is in communication with anadapter769 provided on the proximal extremity of thetube767. Theadapter769 is provided with abody770 formed of a suitable material such as plastic and is provided with abore771 extending therethrough. Theadapter769 is provided with aside arm772 which carries a conventional Luer-type connection and provides anirrigation port773 in communication with thebore771. Athumb screw774 threadedly mounted on thebody770 carries acylindrical protrusion776 adapted to compress an o-ring777 carried by thebody770 into engagement with a therapeutic catheter of the type hereinafter described. Aradiopaque tip marker778 of a suitable type, as for example one formed as a platinum-iridium band778 is provided on the distal extremity of the flexibleelongate element767 to facilitate positioning of the irrigation catheter as hereinafter described.
• Operation of the apparatus shown in FIGS. 26 through 36 in performing the method of the present invention for treating occluded vessels may now be briefly described as follows utilizing the cartoons which are shown in FIGS.[0189]37-43. Let it be assumed that it is desired to treat avessel781 in the human body as for example a saphenous vein graft having at least a partial occlusion orstenosis782 which is formed by plaque in the vessel. Themain catheter651 is introduced into the body through a conventional procedure such as for example by making an incision into the femoral artery in a leg of the patient.
• Thereafter the[0190]main catheter651 can be introduced into the femoral artery by use of a large conventional guiding catheter because themain catheter651 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 catheter786 of the type shown in FIG. 37 can be utilized which can be introduced through themain catheter651. Utilizing such a catheter, themain catheter651 can be inserted independently through a conventional sheath (not shown) in the femoral artery and thereafter the guiding catheter786 is introduced through themain catheter651 so that itsdistal extremity789 is in the vessel. Alternatively, the guiding catheter786 can be deployed into themain catheter651 and the guiding catheter786 introduced at the same time into the femoral artery.
• The guiding catheter[0191]786 is conventional and thus will not be described in detail. It consists of a flexible elongate tubular member787 (see FIG. 37) formed of a suitable material such as plastic having proximal anddistal extremities788 and789. Thedistal extremity789 is provided with a preformed bend as shown. Anadapter792 is mounted on the proximal extremity788 and consists of a body793 in the form a wye in which the central leg794 is provided with a flow passage (not shown) therein in communication with the central lumen (not shown) extending from the proximal extremity788 to thedistal extremity789 of the flexible elongatetubular member787. The body793 is provided with aside leg796 which also is in communication with a lumen (not shown) extending from the proximal extremity788 to thedistal extremity789. Aknob797 carrying an o-ring (not shown) secures theadapter792 to the proximal extremity788 with a fluid-tight seal. Anotherknob798 is provided which is carried by the central leg794 of the body793 and is provided with an o-ring (not shown) which can be moved to close the flow passage in the central leg794, or alternatively it can be opened to receive a guide wire which can be utilized for advancing the guide catheter786 if that be necessary and then forming a fluid-tight seal with respect to the guide wire.
• Assuming that the guiding catheter[0192]786 has been inserted into themain catheter651 before insertion of themain catheter651 into the femoral artery, both catheters can be inserted in unison while advancing the distal extremity of the guide catheter786 so that it precedes the distal extremity of themain catheter651 and serves to guide themain catheter651 into the vessel of interest, as for example thevessel781 having thestenosis782 therein. Themain catheter651 is then advanced so that its distal extremity is at the proximal side of thestenosis782. By way of example, themain catheter651 can be advanced through the aortic arch of the heart and thence into a saphenous vein graft so that theocclusion balloon669 on its distal extremity is positioned proximal of thestenosis782. As soon as this has been accomplished, the guiding catheter786 can be removed.
• As soon as the distal extremity of the[0193]main catheter651 has been deployed so that it is just proximal of thestenosis782 to be treated, an assembly shown in FIG. 38 is introduced into themain catheter651. This assembly can be provided by preloading theirrigation catheter766 onto thetherapeutic catheter801 by inserting the distal tip of thetherapeutic catheter801 through the fitting769 of theirrigation catheter766 and advancing thetherapeutic catheter801 until itstherapeutic balloon809 exits from theirrigation catheter766. The balloon-on-a-wire catheter701 also is preloaded by removing thevalve attachment746 and then inserting theproximal end703 into the guide wire lumen at the distal tip of thetherapeutic catheter801 and then advanced proximally until the proximal end protrudes out of the proximal end of the therapeutic catheter. Thevalve attachment741 is then reattached to theproximal end703. Thepreassembled irrigation catheter766, thetherapeutic catheter801 and the balloon-on-a-wire catheter701 are then introduced in unison as an assembly into themain catheter651. The balloon-on-a-wire device701 is then advanced until the distal extremity is near the distal extremity of themain catheter651 but before the distal extremity has been advanced through thestenosis782.
• Let it be assumed that it is now desired to inflate the[0194]occlusion balloon669 carried by themain catheter651. This can be accomplished in a suitable manner such as with an inflation-deflation device represented schematically by asyringe802 secured to the fitting687 (see FIG. 38) and supplying a balloon inflation fluid through theballoon inflation lumen662 to inflate theocclusion balloon669 to an occlusion pressure ranging from 1 to 3.9 atmospheres and preferably approximately one to two atmospheres to engage the side wall forming thevessel781 to occlude thevessel781 and to prevent further blood flow through the vessel and to thereby provide a workingspace803 distal of theocclusion balloon669. As soon as theocclusion balloon669 has been inflated, the balloon-on-a-wire device701 can be advanced across the lesion orstenosis782 until the deflatedocclusion balloon711 carried thereby is distal of thestenosis782. It is safe to cross thestenosis782 because the flow of blood through thestenosis782 has been occluded by theocclusion balloon669. Thus if any of the plaque forming the stenosis is dislodged by theocclusion balloon711 on the balloon-on-a-wire device701 as theocclusion balloon711 is crossing thestenosis782, the plaque particles oremboli804 will not be carried off by blood. The positive pressure of blood in secondary collaterals or vasculature will prevent emboli from traveling downstream into the secondary vasculature. If desired, aspiration can be supplied to the workingspace803 encompassing thestenosis782 by placing a suitable vacuum connected to the fitting689 of the main catheter.
• The[0195]occlusion balloon711 can then be readily inflated by use of asyringe805 secured to the fitting751 of the removable valve fitting orattachment741 of the balloon-on-a-wire device701 proximal of the fitting686 and accessible outside the body of the patient. Theocclusion balloon711 is inflated (see FIG. 39) to at least approximately one to two atmospheres to bracket the stenosis and to determine the size of the workingspace803 to provide a chamber. It should be appreciated that the size of this working space orchamber803 can be adjusted by changing the position of theocclusion balloon711 in thevessel781. If desired, this can be accomplished while theocclusion balloon711 is inflated.
• Now let it be assumed that the[0196]occlusion balloon711 has been inflated with theappropriate working space803 and that it is desired to introduce atherapeutic balloon catheter801 into the workingspace803 to treat thestenosis782. If thetherapeutic catheter801 is not in themain catheter651 as hereinbefore described, this can be readily accomplished in the present invention by inserting aplug mandrel756 into the open end of thelumen706 of theguide wire702. After theplug mandrel756 has been inserted, thesyringe805 can be removed after which the thumb screws748 and763 can be loosened to permit the o-rings therein to become decompressed and to release theguide wire702 and theplug mandrel756 to permit the fitting orvalve attachment741 to be slipped off to provide a proximal end on theguide wire702 which is free of obstructions. During removal of the valve attachment or fitting741, theocclusion balloon711 remains inflated and continues to be disposed distally of thestenosis782. Theocclusion balloon669 also remains inflated because thesyringe802 remains attached to the fitting686 and is disposed proximal of thestenosis782.
• The conventional[0197]therapeutic catheter801 then can be delivered over theguide wire702 if it is not already present. Thetherapeutic catheter801 is provided with a flexible elongatetubular member806 having proximal and distal extremities807 and808 with a central flow passage (not shown) extending between the same. Atherapeutic balloon809 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 elongatetubular member806 through anadapter811 mounted on the proximal extremity807. Thetherapeutic balloon809 can be considered to be means for performing work carried by the distal extremity808 of the flexible elongatetubular member806. Theadapter811 can be removable of the type hereinbefore described or alternatively can be permanently attached thereto. Assuming that it is a removable adapter, theremovable adapter811 is provided withknobs812 and813 carrying o-rings (not shown) adapted to establish fluid-tight seals with the flexibleelongate member806 and theplug mandrel756, respectively. It is also provided with aninflation port816 similar to those hereinbefore described which is in communication with the inflation lumen (not shown) provided in the flexible elongatetubular member806 for inflating thetherapeutic balloon809.
• After the[0198]balloon catheter801 has been positioned by the use of radiopaque markers (not shown) conventionally employed in such devices, thetherapeutic balloon809 is disposed so that it is in general alignment with thestenosis782 as shown in FIG. 39. Thetherapeutic balloon809 is then inflated in a conventional manner to perform work by use of an inflation-deflation device schematically represented by the syringe817 attached to theinflation port816 to the desired pressure to compress the plaque forming thestenosis782 as shown in FIG. 40 to increase the size of the opening through thestenosis782 in thevessel781.
• Let it be assumed that during the compression of the plaque forming the[0199]stenosis782,additional emboli804 are formed as shown in FIG. 41 by pieces of plaque becoming dislodged from theplaque782 within thevessel781. Let it also be assumed that it is desired to remove these emboli before deflation of the occlusion balloons669 and711 disposed proximally and distally of thestenosis782. To accomplish this, thetherapeutic balloon809 is deflated by use of the syringe817. As soon as this has been accomplished, a saline solution can be introduced through theirrigation catheter766 by connecting atube819 carrying the saline solution from a suitable source as for example a free or pressurized saline bag (not shown) and delivered through the irrigation port orside arm772 where it is carried through the large central lumen of theirrigation catheter766 so that the saline solution is discharged into the workingspace803 disposed between the occlusion balloons711 and669 as shown in FIG. 41. At the same time suitable aspiration means is connected to theaspiration port689 of theadapter686 and as shown can consist of a hand operatedbulb821 which has a oneway check valve822 therein connected to the fitting689.
• The[0200]bulb821 is provided with another one-way check valve823 which is connected to aflexible collection bag824. Thebulb821 makes it possible to generate a vacuum corresponding approximately to 3-30″ of mercury. Thus, by compressing thebulb821 by hand, it is possible to create suction within the chamber orspace803 formed in the vessel between the occlusion balloons669 and711 each time thebulb821 is compressed and released. Alternatively, the aspiration can be accomplished by use of a syringe in place of thebulb821 and thecollection bag824. Saline liquid supplied through theirrigation catheter766 carrying the emboli818 is aspirated through thecentral lumen657 of themain catheter651. The aspirated liquid in each cycle of operation created by pressing thebulb821 is delivered to thecollection bag824. With such a procedure it has been found that it is possible to aspirate emboli as large as 600 μm. Such removal can be assured by observing when clear liquid exits outside the body from theaspiration port691. 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 thetherapeutic catheter801 after deflating thetherapeutic balloon809. The irrigation catheter can be advanced over the balloon-on-a-wire device701 until the distal tip is just proximal of theocclusion balloon711 as shown in FIG. 42 to provide a greater flow of saline and faster aspiration.
• After all of the[0201]emboli804 have been removed, introduction of saline through thetube819 is halted. It should be appreciated that the ports for irrigation and aspiration can be reversed in function if desired. Thereafter, theocclusion balloon711 is deflated by removing theplug756 and utilizing asyringe805, after which theocclusion balloon669 is deflated permitting blood flow to be reestablished in thevessel781. Alternatively, theocclusion balloon669 can be first deflated and aspiration commenced at that time, permitting emboli trapped distally of theocclusion balloon669 by blood flowing from the proximal side of theocclusion balloon669 to be aspirated through thecentral lumen657. In order to prevent excessive expansion of thevessel781 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[0202]plaque782, 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 theocclusion balloon669 can be reinflated by thesyringe805 and theocclusion balloon711 can be reinflated by inserting theremovable valve attachment741 if it has been removed of the balloon-on-a-wire device701 and utilizing thesyringe803 to reinflate theocclusion balloon711. Theplug mandrel756 can be inserted to keep theocclusion balloon711 inflated after which thevalve attachment741 can be removed.
• A conventional stent delivery catheter[0203]826 carrying astent827 on itsflexible shaft828 is introduced over the balloon-on-a-wire device701 and delivered to the site of the dilated stenosis782 (see FIG. 43). Thestent827 can be of the self-expanding type or of the type which can be expanded by a balloon (not shown) carried by the catheter826 by connecting asyringe829 to anadapter830 of the type hereinbefore described of the stent delivery catheter826. After thestent827 has been deployed in the dilatedstenosis782, the stent delivery catheter826 can be removed after which theocclusion balloon711 can be deflated followed by deflation of theproximal balloon661 in the manner hereinbefore described. Also it should be appreciated that if desired in connection with the deployment of the stent delivery catheter826 before it is removed but after deflation of its balloon (not shown), it may be desirable to again flush the working space orchamber803 between the occlusion balloons669 and711 of emboli which may be dislodged during the delivery and deployment of the stent. Theirrigation catheter766 can be deployed in the same manner as hereinbefore described with a saline irrigation solution supplied to the workingspace803 in the manner hereinbefore described and liquid aspirated therefrom by the use of thebulb821 in the manner hereinbefore described.
• 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[0204]831 (see FIG. 44) is provided which is very similar to themain catheter651 with the exception that theadapter832 provided on the proximal extremity is provided withcatheter ports833 and834 which are in communication with the largecentral lumen657 extending the length of the main catheter. Thecatheter ports833 and834 have a construction similar to the exchange catheter andtherapeutic catheter port692 hereinbefore described in connection with themain catheter651. These twocatheter ports833 and834 are necessary because in a carotid procedure, two balloon-on-a-wire devices are utilized. The main catheter should be larger, as for example as large as 12 French, to provide a larger central lumen to accommodate the two balloon-on-a-wire devices.
• One of the balloon-on-a-wire devices can be substantially identical to the balloon-on-[0205]a-wire device701 described. The other balloon-on-a-wire device835 as shown in FIG. 45 differs from thedevice701 shown in FIG. 30 in that in place of theremovable valve attachment741 there is provided a fixedadapter836 which consists of abody837 provided with diametrically extendingwings838 to facilitate grasping of theadapter836. Thebody837 is provided with abore839 which is in communication with thelumen706 in theguide wire702. The adapter is provided with a Luer-type fitting840 to provide a balloon inflation port.
• Operation and use of the apparatus of the present invention in performing a procedure in a carotid artery is shown in the cartoons in FIGS.[0206]46-50. Let it be assumed that it is desired to perform a procedure with the apparatus of the present invention on a carotid artery in a patient, as for examplecommon carotid841 which branches into anexternal carotid842 and aninternal carotid843 and that there is a narrowing or astenosis844 in theinternal carotid843 near the bifurcation into the external andinternal carotids842 and843. Themain catheter831 can be introduced in the manner hereinbefore described with respect to a saphenous vein graft. For example it can be introduced through the femoral artery in the leg and then advanced into the aortic arch up into thecommon carotid841 until theocclusion balloon669 carried thereby is near the bifurcation as shown in FIG. 46. Theocclusion balloon669 is then inflated to at least one atmosphere as shown in FIG. 47 to form a seal to occlude thecommon carotid841 and to temporarily stop the flow of blood to the face and brain of the patient through thecommon carotid841 and to provide a workingspace845 distal of theocclusion balloon669. The inflation is accomplished by suitable means as for example asyringe846 secured to the balloon inflation fitting687. Thereafter, a balloon-on-a-wire device831 of the type shown in FIG. 45 is introduced through thecatheter port833 and advanced through thecentral lumen657 of themain catheter831 after which the distal extremity is guided into theexternal carotid842 so it is disposed beyond the bifurcation. Theocclusion balloon711 carried by the distal extremity is then inflated by suitable means such as asyringe847 secured to theattachment836 to occlude the external carotid. As hereinbefore pointed out, theballoon711 is an occlusion balloon that typically is inflated to a suitable occlusion pressure as for example one to two atmospheres.
• Another balloon-on-a-wire device such as the balloon-on-[0207]a-wire device701 is then introduced through thecatheter port834 and advanced through the central passage orlumen657 until it exits from themain catheter831 after which it is guided into theinternal carotid843 past thestenosis844 so that theocclusion balloon711 is distal of thestenosis844. Theocclusion balloon711 is then inflated as shown by the dotted lines in FIG. 47 by the use of asyringe848 secured to the inflation port carried by theremovable valve attachment741. Thus, the limits of the working space orchamber845 are defined by the occlusion balloons669 and711. As soon as theballoon711 has been inflated, the balloon inflation lumen can be plugged in the manner hereinbefore described by the use of a plug mandrel756 (see FIG. 48). It should be appreciated even though theguide wire702 and theocclusion balloon711 carried thereby may dislodge particles from the plaque forming thestenosis844, the dislodged particles will not travel to the brain because the common carotid supplying blood to theinternal carotid843 has been occluded by theocclusion balloon669.
• The[0208]removable valve attachment741 can then be removed in the manner hereinbefore described so that the proximal extremity of theguide wire702 is free of obstructions as shown in FIG. 68. Thereafter theirrigation catheter766 can be introduced over theguide wire702 and thence into theport834 until its distal extremity extends beyond the distal extremity of themain catheter831. Atherapeutic balloon catheter801 of the same type as hereinbefore described can then be introduced through theirrigation catheter766. It should be appreciated that if desired, the therapeutic balloon catheter can be preloaded into theirrigation catheter766 and theirrigation catheter766 and thetherapeutic balloon catheter801 can be introduced in unison. Assuming that theirrigation catheter766 has been introduced first, thetherapeutic balloon catheter801 is introduced through theirrigation catheter766 until it extends beyond the distal extremity of theirrigation catheter766 and is moved into the workingspace845 until thetherapeutic balloon809 carried by the distal extremity thereof is in registration with thestenosis844. Thetherapeutic balloon809 is then inflated as shown in FIG. 48 by the use of an inflation/deflation device851 represented schematically by a syringe to a suitable therapeutic pressure to compress the plaque forming thestenosis844 to dilate the stenosis to increase the size of the flow passage through thestenosis844. Thetherapeutic balloon809 can then be deflated. In theevent emboli804 are created as hereinbefore described by the passage of thetherapeutic balloon809 through the stenosis, theseemboli804 can be removed as shown in FIG. 49 by introducing a saline solution through thetube819 and into theirrigation port773 of theirrigation catheter766 to cause a saline solution to be discharged into the space formed between the twoocclusion balloons711 and669. To achieve a more effective aspiration, the distal tip of theirrigation catheter766 can be moved through thestenosis844 to just proximal of theocclusion balloon711. Aspirate is removed through theaspiration port689 through the use of thebulb821 and thecollection bag824 to remove the saline solution carrying with it theemboli804 which may have been created and deposit the same in thecollection bag824. This irrigation and aspiration can be carried on for a suitable period of time as for example 5 to 30 seconds after which the occlusion balloons711 in both of thebranches842 and843 can be deflated and thedevices701 and835 can be removed along with thecatheter801 carrying thetherapeutic balloon809. Similarly, theocclusion balloon669 can be deflated to permit blood to flow into thecommon carotid841 and the external andinternal carotids842 and843. Alternatively, the sequence of deflation of the balloons can be carried out in the manner hereinbefore described in connection with a vessel without a bifurcation.
• In the event it is desired to deliver a stent into the dilated[0209]stenosis844, this can be accomplished by reinflating theocclusion balloon669 and then reinflating the occlusion balloons711 in both of the branches after which a balloon stent delivery catheter826 of the type hereinbefore described can be delivered over theguide wire702 in the same manner as thetherapeutic balloon catheter766 and delivered into the desired location and then deployed in the dilatedstenosis844. After thestent827 has been deposited and the balloon of the stent delivery catheter826 is deflated, the irrigation and aspiration procedures hereinbefore described can be repeated to remove any emboli within the space formed between the occlusion balloons711 and669. The stent delivery catheter826 can be removed. After a suitable period of irrigation and aspiration, as for example 5 to 30 seconds, theocclusion balloon711 can be deflated after which theocclusion balloon669 can be deflated and the balloon-on-a-wire devices701 and835 removed along with themain catheter652.
• 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.[0210]
• The desire to eliminate the use of a large guiding catheter for use with the[0211]main catheter651 was hereinbefore discussed. Also, it was hereinbefore disclosed that themain catheter651 can be inserted independently through a conventional sheath (not shown) in the femoral artery and thereafter a smaller conventional guiding catheter786 is introduced through the main catheter so that itsdistal extremity789 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 themain catheter651 which is shaped in a predetermined manner. For example, in themain catheter651ashown in FIG. 26A there is provided in the distal extremity a conventional Judkins left shape and in the main catheter651bshown in FIG. 26B there is provided in the distal extremity a conventional Judkins right shape. Other than the shaping of the distal extremities as hereinbefore described, themain catheters651aand651bare constructed in a manner very similar to thecatheter651 and are provided withocclusion balloons669 as shown.
• Since the[0212]main catheters651aand651bare 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 themain catheter651 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[0213]irrigation catheter766 hereinbefore described in FIG. 36, it should be appreciated as shown in FIGS. 36A and 36B that irrigation catheters766aand766bcan be provided which have soft distal extremities to provide additional flexibility and trackability and thereby reduce trauma in vessels through which they are introduced. Thus in the irrigation catheter766ashown in FIG. 36A, the main portion of the flexible elongatetubular member767 which can be considered to be the shaft can have a greater stiffness than thedistal portion767aof the distal extremity. This can be readily accomplished by utilizing a plastic such as Pebax and Hytrel of various desired durometers. For example, themain shaft767 can have a durometer ranging from 80-100 whereas thedistal portion767acan have a durometer ranging from 50-70. The cylindrical tip767cwith a rounded forward edge as shown is provided with a still lower durometer as for example 35-55 durometer. Thus it can be seen that there has been provided an irrigation catheter which has a very soft tip and which has a distal portion in the distal extremity which is very flexible to permit tracking and to reduce trauma.
• In the irrigation catheter[0214]766bshown in FIG. 36, theshaft767 can have a durometer ranging from 80-100 whereas theportion767acan have a durometer ranging from 60-70 and which has aportion767bformed of the same durometer material that is inclined inwardly and distally to reduce the size of the opening for the passage or lumen768 as shown. Thetip767 which can be formed of a low durometer as for example 35-55 durometer is mounted on thedistal extremity767b.In order to enhance the flow of irrigation fluid from the lumen768 a plurality ofholes857 is circumferentially distributed around theportion767ato augment the flow of irrigation fluid other than through the passage856. The use of the embodiments766aand766bof the irrigation catheter is very similar to that hereinbefore described with theirrigation catheter766 shown in FIG. 36. It should be appreciated that if differing stiffnesses are desired for themain catheters651 and831, the same concepts as disclosed for theirrigation catheter766 can be utilized by selecting materials having desired durometers for various portions of the catheters.
• Another embodiment of the balloon-on-a-wire device is shown in FIGS. 51 and 52 in which the balloon-on-a[0215]wire device901 is in many respects very similar to the balloon-on-a-wire device701 shown in FIG. 30 as hereinbefore described. The balloon-on-a-wire device901 consists of a flexible elongate member in the form of aguide wire702 having proximal anddistal extremities703 and704 with alumen706 extending therethrough. A removable valve attachment or fitting741 is provided on theproximal extremity907. Aplug mandrel756 is carried by theremovable valve attachment741 for use in plugging thebore706 when necessary. Anelastomeric balloon906 is provided on thedistal extremity704 and is provided with proximal anddistal extremities907 and908. Theballoon906 has a suitable length as for example 10 millimeters and a suitable diameter when collapsed or deflated of 1 mm. In order that theballoon906 assume a generally rectangular shape as viewed in cross-section as shown in FIG. 51 with generally right angle comers, theballoon906 is provided with spaced-apartcylindrical regions906aand906bof greater thickness than an intermediate portion906c.For example,portions906aand906bcan have a thickness of 0.006″ to 0.010″ and portion906cof 0.003″ wall thickness. Such a balloon when inflated will have a squareness as illustrated by the dotted lines in FIG. 51. This squareness of the balloon comers helps to assure that emboli will not become entrapped between the balloon and the vessel wall and thereby will not roll by the balloon as it is moved in the vessel.
• An[0216]elongate slot911 is ground into the distal extremity of theguide wire702 to a suitable depth which is in excess of one half of the diameter of theguide wire702. Theslot911 is in communication with thelumen706 and opens into the interior of theballoon906. A taperedcore wire913 is mounted in thedistal extremity704 of theguide wire702. Thecore wire913 is provided with aportion913awhich has a progressive decrease in diameter extending from the proximal extremity to a portion913bwhich is generally of a uniform diameter of a suitable size, as for example 0.003″ and is formed into abend916 and extends proximally along theslot916 and proximally thereof where it is secured to theguide wire702 by suitable means such as an adhesive918. Acoil spring921 formed of a suitable material such as stainless steel or platinum extends over theslot911 and proximally and distally of theslot911 and is secured thereto by suitable means as solder922. Positioned in this manner, thecoil921 generally circumscribes the inner circumference of theballoon906 and serves to protect theballoon906 from any sharp edges as for example sharp edges formed by theslot911 in thecoil wire702. A tip coil926 formed of a suitable radiopaque material such as a platinum or a platinum alloy is mounted over the distal extremity of theguide wire702 and secured thereto by suitable means such assolder927. The distal extremity of the tip coil926 which may have a suitable length, as for example 3 mm, is bonded to the core wire913bby a solder928 which encloses thebend916 and provides a rounded forwardly protruding surface929. Thedistal extremity908 of theballoon906 is secured to thecoils921 and926 by an adhesive931. Similarly, theproximal extremity907 of theballoon906 is secured to theguide wire702 and the portion913bby an adhesive932.
• The balloon-on-[0217]a-wire device901 can be utilized in the same manner as the balloon-on-a-wire device701 hereinbefore described. It is believed that the balloon-on-a-wire device901 has several desirable features. For example theballoon906 is protected from any sharp edges by thecoil spring921. Theslot911, in addition to providing a means for inflating the balloon, also serves to provide a progressive weakening of the distal extremity of theguide wire702 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-awire 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.[0218]
• It should be appreciated that it may be possible to eliminate the use of the occlusion balloons[0219]711 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 theocclusion balloon669 is inflated.
• Another embodiment of a catheter apparatus incorporating the present invention for treating occluded vessels is shown in FIGS. 53 and 54. As shown therein, the catheter apparatus[0220]951 consists of a flexibleelongate member952 similar to those hereinbefore described which is provided with proximal anddistal extremities953 and954. Aconventional adapter956 is mounted on the proximal extremity and is provided with a Tuohy-Borst fitting957 which is in communication with a large central lumen958 extending from the proximal extremity953 to thedistal extremity954. An aspiration fitting961 is provided on theadapter956 as well as an irrigation fitting962, both of which are in communication with the central lumen958. However, it should be appreciated that if desired separate lumens can be provided in the flexibleelongate member952 for both of thefittings961 and962.
• Self-expanding sealing means[0221]966 is mounted on thedistal extremity954. This self-expanding sealing means966 can take any suitable form. For example, as shown it can consist of a braided structure967 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 braid967 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 means966 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[0222]967 with a covering968 of a suitable material such as a polymer which extends over the braided structure967 and which moves with the braided structure967 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[0223]966 so that the apparatus can be inserted into thevessel781 and consists of anelongate sleeve1071 having proximal anddistal extremities1072 and1073 and a bore1074 extending from the proximal extremity1072 to thedistal extremity1073. Acollar1076 is mounted on the proximal extremity1072 of thesleeve1071 and is positioned near theadapter956. Thecollar1076 serves as means for retracting the sleeve as shown in FIG. 54 to uncover the self-expanding sealing means966 after the catheter has been deployed to permit the self-expanding sealing means966 to expand and form a seal with the arterial vessel adjacent the stenosis to be treated.
• Another embodiment of a catheter apparatus for treating occluded vessels incorporating the present invention is shown in FIGS. 55 and 56. As shown therein, the apparatus[0224]1081 consists of a guidingcatheter1082 having proximal and distal extremities1083 and1084. As shown, the distal extremity1083 is provided with a pre-formed bend of a conventional type. Aconventional attachment1086 is mounted on the proximal extremity1083. Self-expanding seal means1091 is mounted on the distal extremity1084 and is of the type hereinbefore described in connection with the embodiments shown in FIGS. 53 and 54. A sleeve1096 similar to thesleeve1071 of the previous embodiment is provided in the present embodiment for encasing the self-expanding seal means1091 and for releasing the same after it has been disposed in an appropriate position within a vessel adjacent the occlusion to be treated. Thus a sleeve1096 is provided having proximal anddistal extremities1097 and1098 and having a bore1099 extending from the proximal extremity to the distal extremity which is sized so that it can receive theguide catheter1082. It is provided with a collar1101 on its proximal extremity which is adapted to be disposed outside the patient and which is adapted to be grasped by the physician for pulling the sleeve1096 proximally to uncover the self-expanding seal1091 after the apparatus has been deployed to permit the self-expansion of the sealing means1091 to form a seal with the vessel wall is shown in FIG. 56.
• 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[0225]1081 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 sleeve1096 to permit the self-expanding seal means1091 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 FIGS. 53, 54,55 and56.
• 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.[0226]
• It will be appreciated that certain variations of the present invention may suggest themselves to those skilled in the art. The foregoing detailed description is to be clearly understood as given by way of illustration, the spirit and scope of this invention being limited solely by the appended claims.[0227]

Claims (24)

What is claimed is:

1. A method of protecting a patient from embolization during a percutaneous procedure on a vessel, comprising the steps of:

providing a guidewire having proximal and distal ends, a proximal and a distal region, an expandable filter associated with the distal region, and a removable sheath which covers the expandable filter and is slidable over the guidewire;

introducing the distal end of the guidewire into the patient's vessel with the sheath covering the expandable filter, and positioning the filter downstream of a region of interest, wherein the sheath and guidewire cross the region of interest;

sliding the sheath toward the proximal end of the guidewire and removing the sheath from the vessel, wherein the expandable filter is uncovered;

deploying the filter;

advancing over the guidewire a stent-deployment catheter to the region of interest; and

expanding the stent at the region of interest,

wherein embolic material is generated and captured before the expandable filter is removed from the patient's vessel.

2. The method ofclaim 1, further comprising the steps of:

removing the stent & deployment catheter from the vessel;

advancing the sheath into the vessel over the guidewire until the sheath covers the expandable filter; and

removing the guidewire and sheath from the vessel.

3. The method ofclaim 1, wherein the stent is deployed by inflation of a balloon.

4. The method ofclaim 1, wherein the stent-deployment catheter is a rapid exchange catheter.

5. The method ofclaim 1, wherein the expandable filter comprises a plurality of struts, each strut having a proximal end in contact with the guidewire and a distal end in contact with the guidewire, and wherein the struts expand to the shape of an eggbeater.

6. The method ofclaim 1, wherein the expandable filter includes a filter mesh.

7. The method ofclaim 1, wherein the expandable filter comprises a plurality of radially biased struts.

8. The method ofclaim 1, wherein the expandable filter comprises a plurality of radially expandable struts which are operable to expand radially outwardly.

9. A percutaneous system having filter and stent deployment capabilities, comprising:

a guidewire having proximal and distal ends, a proximal and distal region, and an expandable filter associated with the distal region;

a sheath which is shaped to receive the guidewire and retain the filter in a contracted condition, and to slidably release the filter to an expanded condition when the sheath moves toward the proximal end of the guide wire;

a catheter having a proximal and a distal end, a proximal and a distal region, and a lumen which slidably receives the guidewire; and

an expandable stent disposed about the distal region of the catheter, the stent having a first diameter which permits intraluminal delivery of the stent into a body passageway and which places the stent in close proximity to the catheter, and having a second expanded diameter adapted to substantially engage a wall of the body passageway,

wherein, during use, the guidewire is positioned across a region of interest, the filter is expanded, and the stent is deployed within the region of interest and remains in place after removal of the catheter from the vessel.

10. The system ofclaim 9 wherein the expandable filter comprises an expansion frame and a filter mesh attached to the expansion frame.

11. The system ofclaim 10, wherein the expansion frame comprises a plurality of struts which, upon activation, bend outwardly to the enlarged condition.

12. The system ofclaim 11, wherein the guidewire includes a distal segment which can be moved longitudinally relative to a proximal segment, and wherein the proximal end of each strut is in contact with the proximal segment and a distal end of each strut is in contact with the distal segment, and wherein the struts expand radially when the distal segment is pulled toward the proximal region of the catheter.

13. The system ofclaim 10, wherein the expansion frame comprises radially biased struts attached to an outer surface of the catheter.

14. The system ofclaim 13, wherein a proximal end of each strut is in contact with the catheter and the distal end of each strut is in contact with the catheter, and wherein the struts expand to the shape of an eggbeater.

15. The system ofclaim 10, wherein the expansion frame comprises an inflation seal.

16. The system ofclaim 15, further comprising an inflation system comprising a first lumen adapted to receive pressurized fluid and a second lumen adapted to evacuate gas, and wherein the inflation seal further includes an entry port in fluid communication with the first lumen of the inflation system and an exit port in fluid communication with the second lumen of the inflation system, so that when fluid is advanced through the first lumen, the fluid enters the inflation seal and forces gas from the inflation seal through the second lumen, thereby purging the system of gas.

17. The system ofclaim 15, wherein the inflation seal comprises a tubular balloon which encloses a chamber and wherein the entry port and exit port are in close proximity, and wherein a septum is disposed between the entry and exit ports.

18. The system ofclaim 9, wherein the stent and the filter are self-expanding.

19. The system ofclaim 9, wherein the stent is removable.

20. The system ofclaim 9, wherein the stent is self-expanding.

21. The system ofclaim 9, wherein the stent comprises stainless steel material.

22. The system ofclaim 9, wherein the stent comprises nitinol material.

23. The system ofclaim 9, wherein the stent has a shape selected from the group consisting of a tube, a sheet, a wire, a mesh, and a spring.

24. The system ofclaim 9, wherein the sheath is shaped to receive the catheter and retain the stent at the first diameter.

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