Angioplasty dilating guide wire - Patent Review 4846174

Claims

What is claimed is:

1. A predilatation catheter for use in angioplasty with a percutaneous transluminal coronary angioplasty (PTCA) catheter of the type having a through lumen and a distal region small enough for insertion in a coronary artery, comprising:

an elongate flexible hollow tubular member;

an elongate core member stiffer than said tubular member and having a diameter less than the inside diameter of said tubular member, said core member positioned inside said tubular member to define an annular inflation passage therebetween;

means forming an inflatable balloon member adjacent the distal end of said tubular member and in fluid communication with said inflation passage with the distal end of said core member extending through the interior of said balloon;

means for sealing the distal end of said balloon to the distal end of said core member;

said tubular member and balloon member having an outside diameter small enough to fit within the through lumen of the PTCA catheter to permit advancing the inflatable balloon member through and beyond the distal end of the PTCA catheter;

a control member receiving the proximal ends of said tubular member and said core member and having means for fluid communication with said annular passage for inflation and deflation of said balloon; and

said control member including means for providing limited relative axial motion of said core member relative to said tubular member to effect axial stretching of said balloon and reduction of profile thereof whereby to facilitate withdrawing the balloon back into the distal end of the through lumen of the PTCA catheter.

2. A predilatation catheter in accordance with claim 1 wherein said tubular member is secured to said control member, and wherein said core member is received in said control member for axial movement therein between predetermined back and forward limit positions therein, whereby said core may move to its back position when said control member is pushed forward to advance the predilatation catheter, and whereby the core member may move to its forward position within said control member, thereby providing for axial stretching of the catheter and balloon as the control member is pulled to withdraw the predilatation catheter.

3. A predilatation catheter in accordance with claim 2 wherein said control member includes means for preventing substantial rotation of said core member while permitting the predetermined axial movement thereof.

4. A predilatation catheter in accordance with claim 1 wherein said control member includes a slot receiving the proximal end of said core member, wherein said core member has a stop member attached thereto within said slot so that said core may move axially of said control member within predetermined limits as the predilatation catheter is advanced or withdrawn while the core member is constrained against rotational movement relative to said control member.

5. A predilatation catheter in accordance with claim 1 wherein said core transitions to a reduced profile at the distal end of the predilatation catheter which is positioned distal to the ostia in use, and wherein the outside diameter of the distal end of the predilatation catheter with its balloon deflated is about 0.018 inch or less.

6. A predilatation catheter for use in angioplasty with a percutaneous transluminal coronary angioplasty (PTCA) catheter of the type having a through lumen and a distal region small enough for insertion in a coronary artery, comprising:

an elongate flexible hollow tubular member;

an elongate core member stiffer than said tubular member and having a diameter less than the inside diameter of said tubular member, said core member positioned inside said tubular member to define an annular inflation passage therebetween;

means forming an inflatable balloon member adjacent the distal end of said tubular member and in fluid communication with said inflation passage with the distal end of said core member extending through the interior of said balloon;

means for sealing the distal end of said balloon to the distal end of said core member;

said tubular member and balloon member having an outside diameter small enough to fit within the through lumen of the PTCA catheter to permit advancing the inflatable balloon member through and beyond the distal end of the PTCA catheter;

conrol means attached to the proximal end of said tubular member and having means for fluid communication with said annular passage for inflation and deflation of said balloon; and

said control means having selectively operable means connected for applying axial force to said core member relative to said tubular member, to transmit the axial force to the distal end of said balloon to effect axial stretching and reduction of profile thereof, whereby to facilitate withdrawing the balloon back into the distal end of the through lumen of the PTCA catheter.

7. A catheter for use in angioplasty, comprising:

an elongate flexible hollow tubular member;

an elongate core member stiffer than said tubular member and having a diameter less than the inside diameter of said tubular member, said core member positioned inside said tubular member to define an annular inflation passage therebetween;

means forming an inflatable balloon member adjacent the distal end of said tubular member and in fluid communication with said inflation passage, the distal end of said core member extending through the interior of said balloon;

means for sealing the distal end of said balloon to the distal end of said core member;

control means attached to the proximal end of said tubular member and having means for fluid communication with said annular passage for applying inflation fluid and pressure thereto to control the inflation and deflation of said balloon; and

said core member having a fluid vent passage extending therethrough from a vent opening in the portion thereof within said balloon to an opening at or adjacent the proximal end of said core member to provide a vent path for removing air from said balloon as it is inflated with pressurized inflation fluid, the cross-sectional dimensions of said vent passage being small enough to provide self sealing of the vent passage with respect to inflation fluid entering the passage as the balloon is being inflated due to capillary action and surface tension of the fluid within the passage, whereby the inflation fluid will move along the passage only until an equilibrium is reached between the inflation pressure and the decay of pressure along the vent passage, thus effectively sealing the vent passage.

8. A catheter according to claim 7 wherein said control means includes means attached to said core member for selectively applying axial force thereto relative to said tubular member to effect axial stretching and reduction of profile of said balloon.

9. A catheter according to claim 7 wherein the outside diameter of the distal end of a catheter with the balloon deflated is about 0.02 inch or less.

10. A catheter for use in angioplasty, comprising:

an elongate flexible tubular member;

an elongate hollow metallic core, said core having a diameter less than the inside diameter of said tubular member, and positioned generally coaxially therein and having a distal end extending beyond the distal end of said tubular member;

an inflatable balloon member having one end attached adjacent the distal end of said tubular member and having its other end attached adjacent the distal end of said core with the balloon member extending around the core and in fluid communication with said annular passage;

a vent hole formed in said core in the portion thereof within said balloon to provide fluid communication between the balloon and the interior of the hollow core;

control means attached to the proximal end of said tubular member and said core and having means for introducing inflation fluid in said annular passage to inflate said balloon;

means for venting the proximal end of said hollow core to permit removal of air displaced from said balloon through said vent hole and said hollow core as the balloon is filled with inflation fluid; and

the inside dimensions of said hollow core being small enough to provide self sealing due to capillary action and surface tension with respect to inflation fluid entering therein through said vent hole as the balloon is being inflated, whereby the inflation fluid will move along the hollow core from the balloon toward the proximal end only to a point at which an equilibrium is reached between the inflation pressure and the decrease of pressure along the hollow core due to capillary action and surface tension, thus effectively forming a fluid seal.

11. A catheter according to claim 10 further including a flexible spring safety tip attached to said core at the distal end therof.

12. A catheter according to claim 10 wherein said control means includes means for attachment to said core for selectively applying axial compression force thereto relative to said tubular member, to selectively axially stretch said balloon to reduce its profile.

13. A catheter according to claim 12 wherein said means for applying axial force includes means for locking said core with respect to said tubular member with said balloon in the stretched condition.

14. Apparatus according to claim 10 wherein said core extends beyond the point of attachment of the distal end of said balloon and tapers to a smaller diameter non-hollow region, and further including a flexible safety spring disposed about and attached to the tip of said core.

15. A catheter according to claim 14 wherein said tip portion of said core tapers to a thin rectangular sectioned ribbon, to provide greater flexibility.

16. A catheter according to claim 10 wherein the outside diameter of the distal end of a catheter with the ballon deflated is about 0.02 inch or less.

17. Angioplasty apparatus for use in opening of very tight stenoses in the coronary arteries, comprising:

a PTCA catheter including an elongate tubular body adapted for introduction into a patient's vascular system, and having an inflatable balloon adjacent a distal end thereof, a through lumen, and a control handle at the proximal end thereof for controlling motion of the catheter in the vascular system and inflation of the balloon in an angioplasty procedure, the distal end of the PTCA catheter being small enough with the balloon uninflated to fit in a coronary artery;

a dilating guide wire adapted for fitting in the through lumen of said PTCA catheter, including an elongate, relatively stiff core, an elongate, relatively flexible hollow tubular member disposed generally coaxially around and along said core, an inflatable balloon at the distal end of the tubular member with its distal end sealed to the distal end of said core, a vent passage extending through said core and communicating with said balloon through a small opening in said core, said vent passage extending substantially to the proximal end but not the distal end of the core, and a control handle attached to the proximal end of said dilating guide wire to control motion thereof and inflation of said balloon with inflation fluid through an annular passage between said tubular member and said core; and

said dilating guide wire having an outside diameter small enough to permit introduction into the through lumen of said PTCA catheter through an access in the control handle thereof, and movement through said lumen to extend the balloon of said dilating guide wire beyond the balloon and distal tip of said PTCA catheter, whereby said dilating guide wire may be used to predilate a stenosis to open it sufficiently for subsequent crossing and dilation by said PTCA catheter without requiring the loss of and reestablishment of the path across the stenosis to change catheters.

18. Apparatus according to claim 17 wherein said dilating guide wire fits witin said PTCA catheter with sufficient contact for torque transmission so that the distal end of said dilating guide wire extending beyond said PTCA catheter can be rotated for steering by manual rotation of the system consisting of said PTCA catheter and said dilating guide wire.

19. Apparatus according to claim 17 wherein said dilating guide wire includes control means associated with said control handle and operatively connected for selectively imparting axial force to said core relative to the hollow tubular member to stretch the balloon of the dilating guide wire to permit withdrawing it back into the through lumen of the PTCA catheter, so that the dilating guide wire may be removed without removal of the PTCA catheter from the patient's vascular system.

20. Apparatus according to claim 17 wherein said vent passage has small enough internal dimensions to cause self sealing of inflation fluid entering therein as said balloon is inflated due to capillary action and surface tension of the inflation fluid in the vent passage.

21. Apparatus according to claim 6 wherein the outside diameter of the distal end of the predilatation catheter with its balloon deflated is about 0.02 inch or less.

22. Angioplasty apparatus for use in opening of tight stenoses in the coronary arteries, comprising:

a PTCA catheter including an elongate tubular body adapted for introduction into a patient's vascular system, and having an inflatable balloon adjacent a distal end thereof, a through lumen, and a control means at the proximal end thereof for controlling motion of the PTCA catheter and inflation of the balloon for dilation, the distal end of the PTCA catheter when said balloon in uninflated being small enough to fit in a coronary artery;

a dilating guide wire adapted for fitting in the through lumen of said PTCA catheter, and including an elongate core, an elongate hollow tubular member disposed generally coaxially around and along said core to define an inflation passage therebetween, an inflatable balloon adjacent the distal end of the tubular member in communication with said inflation passage, and means for sealing the distal end of said balloon so that said balloon can be inflated with inflation fluid applied thereto through said inflation passage, a vent passage in said core extending from the balloon area substantially to the proximal end of the core and communicating with said balloon through a small opening in the core to provide a path for venting displaced air as the balloon is inflated, and control means attached to the proximal end of said dilating guide wire for controlling motion thereof and inflation of said balloon with inflation fluid through said inflation passage; and

said dilating guide wire having an outside diameter small enough, with its balloon uninflated, to permit the dilating guide wire to be placed in the through lumen of the PTCA catheter, and moved therein to extend the balloon area of said dilating guide wire beyond the distal end of said PTCA catheter, and the balloon of the dilating guide wire when inflated having a diameter greater than the uninflated diameter of the balloon of the PTCA catheter, so that the dilating guide wire may be used to predilate a stenosis to open it sufficiently for subsequent crossing and dilation by said PTCA catheter without requiring the loss of and reestablishment of the path across the stenosis to change catheters.

23. Apparatus according to claim 22 wherein said dilating guide wire fits within said PTCA catheter with sufficient contact for torque transmission so that the distal end of said dilating guide wire extending beyond said PTCA catheter can be steered by manual rotation and advancing of the system consisting of said PTCA catheter and said dilating guide wire.

24. Apparatus according to claim 22 wherein said control means of said dilating guide wire includes means operatively connected for selectively imparting axial force to said core relative to said tubular member to stretch the balloon of the dilating guide wire to permit withdrawing it back into the through lumen of the PTCA catheter.

25. Apparatus according to claim 22 wherein said vent passage within said core has small enough internal dimensions to cause self-sealing of inflation fluid entering therein as said balloon is inflated, due to capillary action and surface tension of the inflation fluid within the vent passage.

26. Apparatus according to claim 22 wherein the outside diameter of the distal end of the dilating guide wire with its balloon deflated is about 0.02 inch or less.