Performance enhancement adaptor for intravascular balloon catheter

What is claimed is:

1. An intravascular balloon catheter system, the balloon catheter system comprising:

a catheter shaft having a proximal end, a distal end, an outer surface and at least one lumen extending between the proximal end and the distal end;

an inflatable balloon connected to the shaft at the distal end of the shaft; and

adaptor means independently movable relative to and operable with the balloon, for modifying a performance of the balloon, when the balloon is inflated within the blood vessel.

2. The balloon catheter system of claim 1 wherein the adaptor means further comprises:

a hollow member having a proximal end, a distal end, an outer surface, an inner surface and an opening between the proximal and distal ends; and

positioning means connected to the hollow member, for longitudinally moving the hollow member within the blood vessel, between a wall of the blood vessel and the shaft of the catheter, and for positioning the hollow member so as to contact a surface of the balloon and effect the modified performance of the balloon.

3. The balloon catheter system of claim 2 wherein inflating the balloon secures the hollow member between the wall of the blood vessel and an outer surface of the balloon, with the proximal end and the distal end of the hollow member exposed at a proximal end and a distal end of the balloon.

4. The balloon catheter system of claim 3 wherein the opening is positioned between the balloon and the wall of the blood vessel when the balloon is inflated.

5. The balloon catheter system of claim 4 wherein the opening establishes a flow path for blood past the balloon when the balloon is inflated within the blood vessel.

6. The balloon catheter system of claim 5 wherein the opening is defined by the inner surface of the hollow member.

7. The balloon catheter system of claim 6 wherein the outer surface of the hollow member contacts the blood vessel wall and the outer balloon surface along a contact zone.

8. The balloon catheter system of claim 7 wherein inflating the balloon further creates spaces adjacent the contact zone, between the outer surface of the hollow member and the wall of the blood vessel, the spaces permitting a flow of blood past the balloon while the balloon is inflated within the blood vessel.

9. The balloon catheter system of claim 7 and further comprising:

exposure means through a side wall hollow member for exposing the opening so as to permit a flow of blood transverse to the opening, the flow of blood through the exposure means capable of feeding a side branch of the artery when the balloon and hollow member are positioned across the side branch.

10. The balloon catheter system of claim 9 wherein the exposure means includes a plurality of holes.

11. The balloon catheter system of claim 9 wherein the hollow member comprises a tubular coil of a flat member, and wherein the exposure means comprises spaces between adjacent coils of the hollow member.

12. The balloon catheter system of claim 11 wherein the flat member is a metal member.

13. The balloon catheter system of claim 12 wherein the metal member is radiopaque.

14. The balloon catheter system of claim 11 wherein the flat member is a polymer.

15. The balloon catheter system of claim 9 wherein the hollow member comprises a tubular braid of a wire-like member, and wherein the exposure means comprises gaps between an intersection of the wire like members.

16. The balloon catheter system of claim 4 wherein inflation of the balloon causes the outer surface of the hollow member to contact the wall of the artery, and the inner surface of the hollow member to contact the outer surface of the balloon.

17. The balloon catheter system of claim 16 wherein inflation of the balloon further causes the inner and outer surfaces of the hollow member to expand.

18. The balloon catheter system of claim 17 wherein the opening is defined between the inner surface and the outer surface of the hollow member, and wherein the opening is maintained, when the balloon is inflated within the blood vessel, to permit a flow of blood past the inflated balloon.

19. The balloon catheter system of claim 18 and further comprising:

exposure means through the outer surface of the hollow member for exposing the opening so as to permit a flow of blood transverse to the opening, the flow of blood through the exposure means capable of feeding a side branch of the artery when the balloon and adaptor are positioned across the side branch.

20. The balloon catheter system of claim 19 wherein the exposure means includes a plurality of holes.

21. The balloon catheter system of claim 16 wherein the opening is defined by the inner surface of the hollow member.

22. The balloon catheter system of claim 4 wherein the opening of the hollow member has a predetermined diameter larger than the balloon when the balloon is deflated.

23. The balloon catheter system of claim 22 wherein the hollow member is positionable with respect to the balloon so that the balloon can be positioned within the opening of the hollow member.

24. The balloon catheter system of claim 23 wherein the hollow member is made of a material other than a material of the balloon.

25. The balloon catheter system of claim 24 wherein an outward radial expansion of the balloon is restricted to the predetermined diameter of the hollow member when the balloon is inflated.

26. The balloon catheter system of claim 25 wherein the predetermined diameter of the hollow member increases less than about 2.7% when the balloon is inflated.

27. The balloon catheter system of claim 26 wherein the material of the hollow member has a characteristic so that positioning the hollow member over the balloon increases a pressure tolerance of the balloon between about 12.5% and about 33.3%.

28. The balloon catheter system of claim 27 wherein the proximal end and the distal end of the hollow member are angled.

29. The balloon catheter system of claim 3 wherein the balloon includes an inner cylindrical surface and wherein inflation of the balloon secures the hollow member within the inner cylindrical surface of the balloon, the outer surface of the hollow member engaging the inner cylindrical surface of the balloon to restrict an inward radial expansion of the inner cylindrical surface so as to direct an outward radial expansion of an outer surface of the balloon.

30. The balloon catheter system of claim 29 wherein the inner surface of the hollow member defines the opening, and wherein the opening remains open during inflation of the balloon to permit blood to flow past the balloon for as long as the balloon remains inflated within an artery.

31. An adaptor for modifying a performance of an inflatable, balloon of an intravascular balloon catheter, the adaptor comprising:

a hollow member having a proximal end, a distal end, an outer surface, an inner surface and an opening between the proximal and distal ends; and

positioning means connected to the hollow member, for longitudinally moving the hollow member within a blood vessel, between a wall of the blood vessel and the catheter, and for positioning the hollow member so as to contact a surface of the balloon and effect the modified performance of the balloon.

32. The adaptor of claim 31 wherein the opening has a length of at least 10 millimeters.

33. The adaptor of claim 32 wherein the positioning means is made of a shape memory metal alloy.

34. The adaptor of claim 33 wherein the hollow member is noncompliant in a radial direction.

35. The adaptor of claim 34 wherein the opening of the hollow member is defined by the inner surface of the hollow member.

36. The adaptor of claim 35 wherein the hollow member is made of polyethylene.

37. The adaptor of claim 35 wherein the hollow member is made of polyethylene terephthalate (PET).

38. The adaptor of claim 37 wherein the proximal end and the distal end of the hollow member are biased.

39. The adaptor of claim 36 wherein the hollow member further includes geometric support means for maintaining a radial size of the opening of the hollow member when a force is applied to the outer surface of the hollow member.

40. The adaptor of claim 36 wherein the outer surface and the inner surface of the hollow member define a wall of the hollow member, and wherein the wall includes exposure means for exposing the opening through the wall.

41. The adaptor of claim 40 wherein the exposure means comprises a plurality of holes which are circumferentially spaced about the outer surface of the hollow member.

42. The adaptor of claim 35 wherein the hollow member is comprised of a tubular coil of a flat member, and wherein the exposure means comprises spaces between adjacent coils of the hollow member.

43. The adaptor of claim 42 wherein the flat member comprises a length of a metal material.

44. The adaptor of claim 43 wherein the metal material is radiopaque.

45. The adaptor of claim 42 wherein the flat member comprises a length of a polymer material.

46. The adaptor of claim 35 wherein the hollow member is comprised of a tubular braid of wire-like members, and wherein the exposure means comprises gaps between intersections of the wire-like members.

47. The adaptor of claim 46 wherein the wire-like members comprise strands of a metal material.

48. The adaptor of claim 47 wherein the metal material is radiopaque.

49. The adaptor of claim 33 wherein the hollow member is made of a compliant material.

50. The adaptor of claim 49 wherein the opening is defined between the inner surface and the outer surface of the hollow member.

51. The adaptor of claim 49 wherein the compliant material is silicone.

52. A method of treating an affected region of a blood vessel, the method comprising:

inserting into the blood vessel a catheter comprising a shaft having a proximal end, a distal end and a balloon connected at the distal end of the shaft, the balloon communicating with an inflation lumen of the catheter shaft;

positioning the balloon adjacent the affected region of the blood vessel;

inserting within the blood vessel, between the shaft of the catheter and a wall of the blood vessel, a hollow member having a proximal end, a distal end, an opening between the proximal end and the distal end, and an elongated member attached to the hollow member for positioning the hollow member in contact with a surface of the balloon;

applying a longitudinal force to the elongated member to locate the hollow member within the blood vessel adjacent to the balloon; and

inflating the balloon so as to apply a force to the wall of the blood vessel and a surface of the hollow member, the force securing the hollow member against the balloon so as to effect a performance not capable by the balloon alone.

53. The method of claim 52 wherein the step of positioning the balloon includes:

inflating the balloon so as to apply a force to the wall of the blood vessel; and

deflating the balloon so as to reduce a radial size of the balloon.

54. The method of claim 52 wherein the step of applying the longitudinal force to the elongated member comprises:

positioning the proximal end and distal end of the hollow member near a proximal and a distal end of the balloon, respectively.

55. The method of claim 54 wherein the step of positioning further includes positioning the opening between the balloon and the wall of the blood vessel.

56. The method of claim 55 wherein the step of inflating the balloon causes the opening of the hollow member to create a void past the inflated balloon which allows a flow of blood past the inflated balloon.

57. The method of claim 55 wherein the step of inflating the balloon causes an outer surface of the balloon to contact an inner surface of the hollow member, a radial size of the balloon therefore being restricted to a radial size of the hollow member.

58. A method of modifying an inflatable balloon of a dilatation balloon catheter, the method comprising:

inserting into the blood vessel a catheter comprising a shaft having a proximal end, a distal end and an inflatable balloon connected at the distal end of the shaft, the balloon communicating with an inflation lumen of the catheter shaft;

positioning the balloon adjacent the affected region of the blood vessel;

inserting within the blood vessel, between the shaft of the catheter and a wall of the blood vessel, a hollow member having a proximal end, a distal end, and an elongated member attached to the hollow member for positioning the hollow member in contact with a surface of the balloon;

applying a longitudinal force to the elongated member to locate the hollow member within the blood vessel adjacent to the balloon, with the proximal end and the distal end of the hollow member exposed past a proximal end and a distal end of the balloon; and

inflating the balloon so as to cause at least part of the surface of the balloon to exert a force on a surface of the hollow member, the force securing the surface of the hollow member against the surface of the balloon such that the hollow member establishes a fluid pathway past the inflated balloon.

59. A method of modifying an inflatable balloon of a dilatation balloon catheter, the method comprising:

inserting into the blood vessel a catheter comprising a shaft having a proximal end, a distal end and a compliant, inflatable balloon connected at the distal end of the shaft, the balloon communicating with an inflation lumen of the catheter shaft;

positioning the balloon adjacent the affected region of the blood vessel;

inserting within the blood vessel, between the shaft of the catheter and a wall of the blood vessel, a hollow member having a proximal end, a distal end, an outer surface, an inner surface, the outer surface defining a predetermined diameter of the hollow member along at least a portion of the hollow member and an elongated member attached to the hollow member for positioning the hollow member in contact with a surface of the balloon;

applying a longitudinal force to the elongated member to position the inner surface of the hollow member over the balloon, with the proximal end and the distal end of the hollow member generally aligned with a proximal end and a distal end of the balloon; and

inflating the balloon so as to cause an outer surface of the balloon to expand within the hollow member, the hollow member restricting a radial size of the balloon to the predetermined diameter of the hollow member and increasing an inflation pressure tolerance of the balloon.

Description Submit all comments and votes

BACKGROUND OF THE INVENTION

The present invention relates to the field of intravascular balloon catheters. In particular, the present invention relates to an adaptor which is able to modify the performance of an intravascular balloon catheter to suit a variety of vascular conditions.

Intravascular balloon catheters have been effectively used to treat various maladies associated with the vascular system. For instance, angioplasty has gained wide acceptance as an efficient, effective and alternative method of removing undesirous restrictions caused by tissue growth or lesions on the inner walls of the blood vessels. Such tissue growth or lesions cause a narrowing of the blood vessels called a "stenosis," which severely restricts or limits the flow of blood.

In the most widely used form of angioplasty, a dilatation catheter, which has an inflatable balloon at its distal end, is carefully guided through the vascular system. This guiding process is arduous and time intensive. With the aid of fluoroscopy, a physician is able to position an uninflated balloon across the stenosis. The balloon, often made of a compliant material, is then inflated by applying fluid pressure through an inflation lumen of the catheter to the balloon. The radial size of a compliant balloon is a function of the inflation pressure supplied to the balloon. In other words, the greater the inflation pressure, the greater the radial size of the compliant balloon. This feature of a compliant balloon advantageously permits a physician to alter the inflation pressure (and hence the radial size of the balloon) to suit the size of the blood vessel in which the stenosis is located. Ideally, inflation of the balloon, within the balloon's working inflation pressure range, cracks and compresses the stenosis-causing lesion toward the artery wall to remove the constriction and re-establish acceptable blood flow through the artery.

Some physicians, however, prefer to use a dilatation catheter, under some circumstances, which has a balloon made of a relatively non-compliant material (i.e., a balloon which will retain a given radial size as inflation pressure is increased).

It is often desirable to keep the balloon inflated within the artery for relatively significant periods of time. One disadvantage of many dilatation catheters of the prior art is the complete occlusion of the blood vessel that results while the balloon is inflated. Prolonged complete blockage of a coronary artery results in discomfort to the patient and poses serious risk of damage to the tissue downstream from the occlusion which is deprived of oxygenated blood. These consequences limit the length of time the balloon can remain expanded within an artery to effectively re-open the artery.

Various means for providing passive perfusion of blood through or past the inflated balloon have been permanently incorporated into either the catheter shaft or the balloon. Examples of such perfusion catheters are found in the following prior art references: Baran et al. U.S. Pat. No. 4,423,725; Sahota U.S. Pat. No. 4,581,017; Hershenson U.S. Pat. No. 4,585,000; Horzewski et al. U.S. Pat. No. 4,771,777; Mueller et al U.S. Pat. 4,790,315; Songer et al. U.S. Pat. No. 4,892,519; Goldberger U.S. Pat. No. 4,909,252; Sogard et al. U.S. Pat. No. 4,944,745; Sahota U.S. Pat. No. 4,983,167; Boussignac et al. U.S. Pat. No. 5,000,734; Patel U.S. Pat. No. 5,000,743; Bonzel U.S. Pat. No. 5,002,531; and Sahota European Patent Application 0 246 998.

While perfusion catheters are capable of performing perfusion during balloon dilatation, certain drawbacks exist. For instance, the profile of perfusion catheters is generally considerably larger than that of an ordinary balloon dilatation catheter. The larger profile of perfusion catheters can inhibit and/or prohibit such a catheter from crossing a stenosis, especially when the stenosis is quite narrow. In addition, perfusion catheters known in the art are not capable of providing blood flow to side branches of the artery which occasionally are blocked by the inflated balloon. Finally, the need to use a perfusion catheter usually does not become apparent until after a relatively simple dilatation catheter has been used. Thus, in order to obtain perfusion capability with an intravascular catheter, the ordinary balloon dilatation catheter must be removed from the vascular system, and the arduous and time intensive task of rerouting a perfusion catheter within the vascular system must be undertaken. A replacement of a catheter such as this, under extreme circumstances, is not without adverse risks or consequences.

The ability to safely, successfully and efficiently perform dilatation of an occluded artery would be enhanced if only one relatively simple dilatation balloon catheter could be adapted to a variety of arterial conditions. Furthermore, the ability to perfuse past or to increase the burst pressure and strength of an ordinary, prepositioned dilatation balloon would save considerable economic cost, considerable time and potentially considerable discomfort to the patient.

SUMMARY OF THE INVENTION

The present invention is an adaptor for use with any intravascular balloon catheter, which adapts a balloon of the catheter to a variety of vascular conditions. The adaptor generally includes at least one hollow member, which has a length equal to or greater than a balloon of the catheter, and a thin, elongated positioning member, which permits the hollow member to be advanced within a blood vessel.

In one preferred embodiment, the adaptor is inserted into a guide catheter between the shaft of the balloon catheter and an inner wall of the guide catheter. By applying a longitudinal force to the elongated member, the adaptor is then self-guided between the catheter shaft and a wall of the artery to the balloon. With the balloon deflated, the adaptor is positioned with a surface of the adaptor adjacent a surface of the balloon such that proximal and distal ends of the hollow member are generally aligned with or equidistant to proximal and distal ends, respectfully, of the balloon. Inflation of the balloon secures the surface of the hollow member to the surface of the balloon. So positioned the hollow member supplies a performance not capable by the balloon alone.

In another embodiment, the hollow member is guided to the balloon along a guide wire which is external to the catheter shaft.

In another embodiment, the hollow member is guided to the balloon over the catheter shaft. When a manifold of the catheter is removable, the hollow member is positioned over a proximal end of the catheter shaft by removing the manifold after the catheter has been prepositioned within the artery. When the manifold is not removable, the hollow member is positioned over a distal end of the catheter shaft before the catheter is inserted into the guide catheter. The hollow member is then maintained near the manifold during the positioning of the catheter.

In one preferred embodiment, the hollow member creates a blood perfusion passage, which permits the balloon of a basic dilatation catheter to remain inflated within the artery for an extended period of time while allowing blood to flow past the balloon to tissues downstream from the balloon. Unlike perfusion dilatation catheters, which have relatively large profiles, the use of the adaptor of the present invention for perfusion enables a physician to use a relatively low profile balloon dilatation catheter to cross a blocked region of the artery.

In another embodiment, a side wall of the hollow member includes openings, which expose the blood perfusion passage and permit a flow of blood transverse to the blood perfusion passage. In the event the inflated balloon and hollow member are positioned across a side branch of the artery, the adaptor enables blood to flow into the side branch.

In another embodiment, the adaptor has sufficient longitudinal flexibility and radial rigidity to conform to a bend of the artery while maintaining the blood perfusion passage past the inflated balloon.

In another embodiment, the hollow member is made of a noncompliant material that envelopes the balloon. Upon inflation of the balloon, the hollow member serves to restrict the balloon's radial size, enhance its strength and increase the dilatation force applied to the stenosis. In addition the hollow member is capable protecting the artery in the event of a balloon rupture. Finally, the hollow member is able to decrease the size of the balloon in the event the balloon is too large for the artery requiring treatment.

When a vascular condition is encountered during a balloon catheter procedure for which the balloon catheter is ill-suited, the adaptor of the present invention provides a simple and inexpensive means to achieve a desired performance that would not have been possible by the balloon alone. Use of the hollow member therefore avoids the need for the arduous and time intensive complete exchange of the balloon catheter to accomplish the desired performance.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a first embodiment of the adaptor of the present invention.

FIG. 1A is an end view of the adaptor shown in FIG. 1.

FIGS. 2-2B are perspective views of an artery with a section cut away to demonstrate use of the adaptor of FIG. 1 with a balloon catheter.

FIG. 3 is a cross-sectional view of the adaptor of FIG. 2B taken along line 3--3.

FIG. 4 is a perspective view of an artery with a section cut away showing an alternate method of guiding the adaptor of FIG. 1 through an artery.

FIG. 4A is an enlarged side view of a distal region of a balloon catheter, with a portion of balloon B cut away, to demonstrate another alternative method of using the adaptor of FIG. 1 with a donut-shaped balloon.

FIG. 5-5A are end views of the adaptor shown in FIG. 1 showing alternate connections between the hollow member and the positioning member.

FIG. 6 is a perspective view of a second embodiment of the adaptor of the present invention with a section cut away to show reinforcing fibers embedded in the wall of the adaptor.

FIG. 6A is a cross-sectional view of the adaptor of FIG. 6 taken along line 6A--6A.

FIG. 6B is a cross-sectional view of an alternative embodiment of the adaptor of FIG. 6.

FIG. 7 is a perspective view of a third embodiment of the adaptor of the present invention.

FIG. 8 is a perspective view of a fourth embodiment of the adaptor of the present invention.

FIG. 9 is a perspective view of a fifth embodiment of the adaptor of the present invention.

FIG. 10 is a sectional view of a side branch intersection of an artery with a balloon catheter, shown in perspective, positioned across the side branch.

FIG. 10A is a sectional view of the artery shown in FIG. 10, with the adaptor of FIG. 9 secured across the side branch by an inflated balloon.

FIG. 10B is a sectional view of a bend of an artery showing the adaptor of FIG. 7 secured between an inflated balloon and a wall of the artery.

FIG. 11 is a perspective view of a sixth embodiment of the adaptor of the present invention.

FIG. 12 is a perspective view of a seventh embodiment of the adaptor of the present invention.

FIG. 13 is a perspective view of an artery with a section cut away showing the adaptor of FIG. 12 secured between an inflated balloon and a wall of the artery.

FIG. 14 is a perspective view of the adaptor of FIG. 12 with the support ribs removed.

FIG. 15 is a perspective view of an eighth embodiment of the adaptor of the present invention.

FIG. 16 is a cross-sectional view of the adaptor of FIG. 15 taken along line 15--15.

FIG. 17 is a perspective view of a ninth embodiment of the adaptor of the present invention, which incorporates a sleeve.

FIGS. 18-19 are perspective views of an artery with a section cut away demonstrating the method of using the adaptor of FIG. 17 with a balloon catheter.

FIG. 20 is a perspective view of the sleeved adaptor of FIG. 17 with openings through the sleeve.

FIG. 21 is a perspective view of a tenth embodiment of the adaptor of the present invention.

FIG. 22 is a perspective view of an artery with a section cut away showing the adaptor of FIG. 21 secured between a balloon and a wall of the artery.

FIG. 23 is a perspective view of the adaptor of FIG. 21 with openings through an exterior of the adaptor.

FIG. 24 is a perspective view of an eleventh embodiment of the adaptor of the present invention.

FIG. 25 is a perspective view of an artery with a section cut away showing the adaptor of FIG. 24 secured between a balloon and a wall of the artery.

FIG. 26 is a cross-sectional view of the adaptor of FIG. 24 taken along line 26--26.

FIG. 27 is a perspective view of a twelfth embodiment of the adaptor of the present invention.

FIG. 28 is a perspective view of an artery with a section cut away showing the adaptor of FIG. 27 secured between a balloon and a wall of the artery.

FIG. 29 is a cross-sectional view of the adaptor of FIG. 27 taken along line 29--29.

FIG. 30 is a perspective view of a thirteenth embodiment of the adaptor of the present invention.

FIGS. 31A-31B are side views of the adaptor of FlG. 30.

FIG. 32 is a perspective view of the adaptor of FIG. 30 shown positioned over an inflated balloon.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Perfusion Adaptor 30 (FIGS. 1-5A)

FIG. 1 is a perspective view of perfusion adaptor 30 of the present invention. Perfusion adaptor 30 generally includes hollow member 32 and positioning member 34. Hollow member 32 particularly includes distal end 36, proximal end 38, outer surface 42, inner surface 44 and flow passage 40, which extends from distal end 36 to proximal end 38. As shown in FIG. 1, perfusion adaptor 30 is generally tubular-shaped, with outer surface 42 and inner surface 44 being generally cylindrical. Hollow member 32 also includes radiopaque marker 45, as is known in the art, to provide the physician with a visual reference for accurately positioning hollow member 32 within an artery.

Hollow member 32 has a length equal to or greater than balloons typically used in balloon catheter procedures (i.e., balloons about 10 millimeters to about 50 millimeters long). In one preferred embodiment, hollow member 32 also has an outer diameter which ranges from about 0.010 to about 0.150 inches, and a wall thickness which ranges from about 0.001 inch to about 0.006 inch. The relatively small size of hollow member 32, therefore, makes hollow member 32 well suited to be positioned between a wall of an artery and an inflated balloon without dramatically altering the geometry of the artery. On the other hand, the size of flow passage 40 is adequately large to permit a sufficient amount of blood to flow past an inflated balloon to supply tissues downstream from the balloon, and to minimize the potential for discomfort of the patient in the event the balloon must remain inflated within the artery for an extended period of time.

Hollow member 32 is preferably made of a material or materials, which impart axial flexibility and radial rigidity to hollow member 32. Hollow member 32 is axially flexible to permit hollow member 32 to be advanced through relatively tortuous paths often encountered during intravascular catheter procedures. Hollow member 32 is also radially rigid to prevent flow passage 40 from collapsing when hollow member 32 is positioned between artery wall 62 and inflated balloon 54 (as shown in FIG. 2D and 3). In one embodiment, hollow member 32 of the present invention is extruded from a suitable polymer, such as polyethylene.

Positioning member 34 is an elongated structure which includes distal end 46 and proximal end 48. As shown in FIGS. 1-1A, distal end 46 is generally aligned with distal end 36 of hollow member 32, and positioning member 34 is bonded to inner surface 44 with bonding material 47, such as the epoxy UR3507 from H. B. Fuller. In preferred embodiments, positioning member 34 is made of 304 stainless steel or any shape memory metal alloy, such as NITINOL (nickel titanium alloy). Positioning member 34 has a length greater than typical balloon catheters (i.e., greater than about 130 centimeters), and suitable pushable characteristics to allow hollow member 32 to be advanced within a blood vessel, between a balloon catheter and a wall of the blood vessel, to the balloon of the balloon catheter. In preferred embodiments, positioning member 34 has an outer diameter of about 0.006 to about 0.018 inches.

First Method of Use

FIGS. 2-2B best show one preferred method of using perfusion adaptor 30 of the present invention. FIGS. 2-2B show a perspective view of artery 50 with a section cut away to show standard balloon dilatation catheter 52 positioned within artery 50. For purposes of describing the use of perfusion adaptor 30, balloon 54, which includes distal end 56 and proximal end 58, is positioned adjacent lesion 60 of artery wall 62, as shown in FIG. 2. Perfusion adaptor 30 is inserted into a guide catheter (not shown), which is used in conjunction with catheter 52. Hollow member 32 is then advanced through artery 50 by applying a pushing force to positioning member 34. In one embodiment, perfusion adaptor 30 is self-guiding, with radiopaque marker 45 providing visual feedback necessary to determine the location of hollow member 32 within artery 50.

As is commonly known, inflation of balloon 54 compresses lesion 60, thereby re-opening artery 50, as shown in FIG. 2A. In some instances, adequate compression of lesion 60 is achieved by inflating balloon 54 for a relatively short period of time. In other instances, however, it is desirable or necessary to permit balloon 54 to remain inflated within artery 50 for a period of time which is significant enough to cause extended depletion of oxygen bearing blood downstream from inflated balloon 54. In such instances, where prolonged inflation of balloon 54 within artery 50 is desired or required, balloon 54 is deflated, as shown in FIG. 2A. With balloon 54 deflated, a physician advances hollow member 32 adjacent balloon 54 by applying an appropriate longitudinal force to positioning member 34.

As shown in FIG. 2B, hollow member 32 is positioned with distal end 36 of hollow member 32 generally aligned with distal end 56 of balloon 54, and with proximal end 38 of hollow member 32 generally aligned with proximal end 58 of balloon 54. Balloon 54 is reinflated, thereby re-exerting a dilatation force to artery wall 62 and further securing hollow member 32 between balloon 54 and artery wall 62. With hollow member 32 positioned between balloon 54 and artery wall 62, flow passage 40 permits a flow of blood past balloon 54, thereby permitting balloon 54 to remain inflated with artery 50 for an extended period of time.

FIG. 3 is a cross-sectional view of balloon 54 and perfusion adaptor 30 taken along line 3--3 of FIG. 2B. As shown in FIG. 3, balloon 54 contacts outer surface 42 of hollow member 32 at first side 64, thereby securing outer surface 42 of hollow member 32 against artery wall 62 at second side 66. An outer surface of balloon 54 contacts a substantial portion of artery wall 62 which, due to inflation pressures within the balloon, dilates artery 50. As further shown in FIG. 3, with hollow member 32 inflated between balloon 54 and artery wall 62, sinuses 68A and 68B are formed adjacent hollow member 32. Sinuses 68A and 68B are formed by the interaction of balloon 54, artery wall 62 and outer surface 42 of hollow member 32 from distal end 36 to proximal end 38 of hollow member 32. Sinuses 68A and 68B permit additional flow of blood past balloon 54 when balloon 54 is inflated within artery 50. As further shown in FIG. 3, positioning member 34 occupies a relatively small cross-sectional area of flow passage 40 so as not to interfere with the flow of blood through flow passage 40.

Second Method of Use

FIG. 4 shows an alternate method for advancing perfusion adaptor 30 through an artery. Generally, balloon catheters are known in the art which have a guide wire guide positioned external to and at a distal end of the catheter shaft. The distal guide wire guide allows a guide wire over which the catheter is guided to remain external to the catheter shaft along the entire length of the shaft. This enables a physician to exchange one catheter for another without interrupting the established position of the guide wire across a stenosis of the artery. Examples of such catheters include the following, which are incorporated by reference: Giesy et al. U.S. Pat. No. 4,824,435, European Patent Application 0 344 530 A1 by Advanced Cardiovascular Systems, Inc., and co-pending U.S. Pat. applications Ser. No. 07/782,518 entitled COILED, PERFUSION BALLOON CATHETER, filed Oct. 25, 1991 by M. Arney, and Ser. No. 07/866,998 entitled BALLOON CATHETER FOR DILATATION AND PERFUSION, filed Apr. 9, 1992 by M. Arney.

Perfusion adaptor 30 can alternatively be guided through a vessel over a guide wire of the aforementioned catheter design. FIG. 4 is a perspective view of artery 80 with a section cut away to show balloon catheter 82, which includes distal guide wire guide 84 and guide wire 86. As shown in FIG. 4, perfusion adaptor 30 can be easily advanced over guide wire 86 to balloon 88 by sliding flow passage 40 of hollow member 32 over proximal end 90 of guide wire 86 and then applying a pushing force to positioning member 34. The location of guide wire guide 84 at the distal end of catheter 82 ensures that perfusion adaptor 30 can be advanced only as far as balloon 88. The nominal size of guide wire 86 ensures that flow passage 40 retains adequate flow space for the flow of blood through hollow member 32.

Third Method of Use

FIG. 4A gives an enlarged side view of a distal region of balloon catheter A, with a portion of balloon B cut away to demonstrate another alternative method of using adaptor 30 with a donut-shaped balloon. Donut-shaped balloons are described in detail in the following previously disclosed references: Goldberger U.S. Pat. No. 4,909,252; Bonzel U.S. Pat. No. 5,002,531; and co-pending U.S. Pat. application Ser. No. 07/782,518. The detailed descriptions of the aforementioned references are incorporated by reference herein.

As shown in FIG. 4A, balloon B includes outer surface O, inner surface I and cylindrical space C, which is defined by inner surface I. Cylindrical space C provides a space to accommodate guidewire G and allows balloon B of catheter A to be guided over guidewire G within an artery. With guidewire G positioned within cylindrical space C, adaptor 30 is guidable over guidewire G in a manner similar to that described relative to FIG. 4.

As further shown in FIG. 4A, as balloon B is inflated within blood vessel V, outer surface O radially expands outward and engages wall W of blood vessel V. In addition, inflation of balloon B causes inner surface I to radially expand inward toward guidewire G. In order to halt the inward radial expansion of inner surface I and therefore increase the outward radial dilatation force of outer surface O, adaptor 30 is advanced along guidewire G and positioned within cylindrical space C, with distal end 36 and proximal end 38 of adaptor 30 generally aligned or extending equal distances from proximal and distal ends of balloon B, respectfully. With balloon B partially inflated, cylindrical space C has a diameter which is slightly larger than an outer diameter of hollow member 32, which allows adaptor 30 to be easily maneuvered within cylindrical space C along guidewire G. Further inflation of balloon B causes inner surface I to engage outer surface 42 of adaptor 30, which allows the dilatation force of balloon B to be directed to outer surface O and against wall W of blood vessel V. Furthermore, flow passage 40 of adaptor 30 permits blood to flow past balloon B for as long as balloon B remains inflated within blood vessel V.

As shown in FIG. 5, connection of positioning member 34 to hollow member 32 may be enhanced by flattening a distal portion of positioning member 34 to provide greater surface contact over which bonding material 47 can adhere. As shown in FIG. 5A, hollow member 32 may alternatively include rib 92 so as to create bonding chamber 94 for positioning member 34. Bonding chamber 94 provides a 360.degree. bonding surface for bonding material 47, which ensures a secure connection between positioning member 34 and hollow member 32.

Perfusion Adaptor 100 (FIG. 6-6B)

FIG. 6 is a perspective view of perfusion adaptor 100, which includes all of the features of perfusion adaptor 30 plus support structure 102. A section of FIG. 6 is cut away to better show support structure 102. Support structure 102 is comprised of reinforcing fibers 104, which are woven in the shape of a tube. In the preferred embodiment, as shown in FIG. 6-6A, support structure 102 is embedded into wall 105 by introducing support structure 102 during the extrusion of hollow member 106. Positioning member 107 is attached to hollow member 106 as described previously.

Reinforcing fibers 104 are preferably made of stainless steel or nylon. Alternatively, reinforcing fibers 104 can be a radiopaque metal, such as titanium or a platinum alloy, which allows the physician to monitor the positioning of perfusion adaptor 100 within an artery. Support structure 102 enhances the axial flexibility and radial rigidity of hollow member 106, thereby enhancing the maneuverability of perfusion adaptor 100 while ensuring the flow passage remains open under the force of the balloon.

Support structure 102 can also be associated with hollow member 106 in a variety of alternative ways. For example, as shown in FIG. 6B, support structure 102 is incorporated into hollow member 106 by bonding support structure 102 between outer layer 110 and inner layer 112 of hollow member 106. Alternatively, support structure 102 can be positioned over outer surface 108 of hollow member 106 and secured by any suitable bonding material.

Perfusion Adaptor 120 (FIG. 7)

FIG. 7 is a perspective view of perfusion adaptor 120 o