Balloon catheter having nonlinear compliance curve and method of using

• US 5,447,497 A
• Filed: 05/16/1994
• Issued: 09/05/1995
• Est. Priority Date: 08/06/1992
• Status: Expired due to Term

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Hendrickson, Gary L., Keith, Pete T., Wang, Lixiao, Sogard, David J.
• Primary Examiner(s): MCDERMOTT, CORRINE MARIE
• Application Number:
  US08/243,473
• Time in Patent Office: 477 Days
• Field of Search: 604/96, 604/101, 604/53, 606/191, 606/192, 606/194
• US Class Current: 604/101.02
• CPC Class Codes: A61M 2025/1013 with concentrically mounted balloons, e.g. being independently inflatable
• CPC Class Codes: A61M 2025/1084 having features for increasing the shape stability, the reproducibility or for limiting expansion, e.g. containments, wrapped around fibres, yarns or strands
• CPC Class Codes: A61M 25/1011 Multiple balloon catheters

Abstract

A balloon catheter, having a non-linear compliance curve, made up of a dual layered balloon, one balloon being a Compliant balloon and the other balloon being a Non-Compliant balloon.

Claims

1. A catheter useful for angioplasty comprising:

an elongated catheter tube having a proximal and a distal end and a catheter tube circumference,

a dilating element secured to the distal end of said elongated catheter tube and having an unexpanded circumference greater than the catheter tube circumference, said dilating element having a non-linear compliance curve, said compliance curve having a substantially linear compliant segment and a substantially linear segment of relatively less compliance, and said compliant segment having a slope corresponding to a diameter increase of no more than 10% per atmosphere of increased pressure,

said elongated catheter tube having an inflation lumen extending from its proximal to its distal end, the distal end of said inflation lumen communicating with the interior of said dilating element,

inflation means in communication with the proximal end of said inflation lumen for metering inflation fluid into the inflation lumen and the interior of said dilating element to cause the dilating element to expand in the diametric direction in accordance with its non-linear compliance curve.

2. The invention as set forth in claim 1 wherein the inflation means is operative to expand the dilating element during an initial inflation phase and a secondary inflation phase and the compliant segment of the compliance curve corresponds to the initial inflation phase of the catheter and the relatively less compliant segment corresponds to the secondary inflation phase of the catheter.

3. A catheter useful for angioplasty comprising:

an elongated catheter tube having a proximal and a distal end,

a dilating element secured to the distal end of said elongated catheter tube, said dilating element having a non-linear compliance curve, said compliance curve having a substantially linear compliant segment and a substantially linear segment of relatively less compliance, and said compliant segment having a slope corresponding to a diameter increase of no more than 10% per atmosphere of increased pressure,

said elongated catheter tube having an inflation lumen extending from its proximal to its distal end, the distal end of said inflation lumen communicating with the interior of said dilating element,

inflation means in communication with the proximal end of said inflation lumen for metering inflation fluid into the inflation lumen and the interior of said dilating element to cause the dilating element to expand in the diametric direction in accordance with its non-linear compliance curve; and

wherein the inflation means is operative to expand the dilating element during an initial inflation phase and a secondary inflation phase and the relatively less compliant segment corresponds to the initial inflation phase of the catheter and the relatively compliant segment corresponds to the secondary inflation phase of the catheter.

4. A catheter including a catheter tube and an inflatable balloon portion having a non-linear compliance curve within its usable range as a dilating element, the catheter comprising:

a first balloon, made of a compliant plastic material, having a first low pressure diameter,

a second balloon, made of a low compliant plastic material, having a second low pressure diameter, said first and second balloons being coextensive and located one within the other and having an uninflated circumference greater than the circumference of the catheter tube,

means, for inflating the inner of said balloons, in operative communication with the inner balloon,

said first and second low pressure diameters being unequal such that the compliance curve of the first balloon will be followed during initial inflation until the diameter of the first balloon equals the low pressure diameter of the second balloon and the compliance curve of the second balloon will be followed during further inflation of the balloon portion of the catheter.

5. The invention as set forth in claim 4 wherein the first balloon, made of a compliant plastic material, is the outer balloon and the second balloon, made of a non-compliant plastic material, is the inner balloon.

6. The invention as set forth in claim 4 wherein the first balloon is made of a thermoplastic polymer.

7. The invention as set forth in claim 4 wherein the first balloon is made of a material selected from the group consisting of polyethylene, polyethylene blends, polyethylene copolymers, ionomers, polyesters, polyurethanes, polycarbonates, polyamides, polyvinyl chloride, acrylonitrile-butadiene-styrene copolymers, polyether-polyester copolymers, and polyether-polyamide copolymers.

8. The invention as set forth in claim 4 wherein the first balloon has a compliance curve which provides an increase in diameter of between 15% and 40% when expanded from said first low pressure diameter at 2 atmospheres pressure to an expanded diameter at 6 atmospheres pressure.

9. The invention as set forth in claim 4 wherein the first balloon has a compliance curve which provides an increase in diameter of between 15% and 40% when expanded from said first low pressure diameter at 2 atmospheres pressure to an expanded diameter at 12 atmospheres pressure.

10. The invention of claim 4 wherein the compliance curve of the balloon portion of the catheter has a segment which corresponds substantially to a segment of the compliance curve of the first balloon and which has a slope corresponding to an increase in diameter of no more than 10% per atmosphere of increased pressure.

11. The invention as set forth in claim 4 wherein the first balloon is made of a thermoplastic elastomer.

12. A catheter including an inflatable balloon portion having a non-linear compliance curve within its usable range as a dilating element, the catheter comprising:

a first balloon, made of a complaint plastic material, having a first low pressure diameter,

a second balloon, made of a low compliant plastic material, having a second low pressure diameter, said first and second balloons being coextensive and located one within the other,

means, for inflating the inner of said balloons in operative communication with the inner balloon,

said first and second low pressure diameters being unequal such that the compliance curve of the first balloon will be followed during initial inflation until the diameter of the first balloon equals the low pressure diameter of the second balloon and the compliance curve of the second balloon will be followed during further inflation of the balloon portion of the catheter; and

wherein the first balloon, made of a compliant plastic material, is the inner balloon and the second balloon, made of non-compliant plastic material, is the outer balloon.

13. A catheter including an inflatable balloon portion having a non-linear compliance curve, the catheter comprising:

a first balloon, made of compliant plastic material, having a first low pressure diameter,

a second balloon, made of a non-compliant plastic material, having a second low pressure diameter,

said balloon portion comprising said first and second balloons,

said first and second balloons being located one within the other and said second balloon being the inner balloon,

inflation means in operative communication with the inner balloon, the inflation means being operative to expand the balloon portion during an initial inflation phase and a secondary inflation phase,

said first low pressure diameter being equal to or greater than the second low pressure diameter such that the compliance curve of the second balloon will be followed by the balloon portion during the initial inflation phase until the second balloon ruptures, and the compliance curve of the first balloon will be followed by the balloon portion during the secondary inflation phase of the balloon portion of the catheter.

14. A catheter including an inflatable balloon portion having a non-linear compliance curve,

said balloon portion comprising first and second balloons,

said first balloon having a first low pressure diameter and being formed of compliant plastic material,

said second balloon having a second low pressure diameter and being formed of non-compliant plastic material,

the low pressure diameter of the first balloon being equal to or greater than the low pressure diameter of the second balloon,

said first and second balloons being located one within the other such that the first balloon is the outer balloon and the second balloon is the inner balloon,

inflation means in operative communication with the second balloon, the inflation means being operative to expand the balloon portion during an initial inflation phase and a secondary inflation phase by metering an inflation fluid into the second balloon,

the low pressure diameters of the first and second balloons and their relative locations one within the other being, such that during the initial inflation phase during which inflation fluid is metered to the interior of the second balloon, the second balloon will be inflated and the compliance curve of the second balloon will be followed by the balloon portion until the second balloon ruptures, thereby bringing the inflation means into communication with the first balloon, and whereupon the pressure in the balloon portion is reduced and further metering inflation fluid to the interior of the first balloon will cause the balloon portion to follow the compliance curve of the first balloon.

15. A catheter including a catheter tube and an inflatable balloon portion having a non-linear compliance curve within its usable range as a dilating element, the catheter comprising:

a first balloon, made of a compliant plastic material, having a first low pressure diameter and proximal and distal ends,

a second balloon, made of a low compliant plastic material, having a second low pressure diameter and proximal and distal ends, said first and second balloons being coextensive and located one within the other and connected at the proximal and distal ends, the balloons having an uninflated circumference greater than the circumference of the catheter tube,

means, for inflating the inner of said balloons, in operative communication with the inner balloon,

said first and second low pressure diameters being unequal such that the compliance curve of the first balloon will be followed during initial inflation until the diameter of the first balloon equals the low pressure diameter of the second balloon and the compliance curve of the second balloon will be followed during further inflation of the balloon portion of the catheter.

16. A method of using an angioplasty balloon catheter, the catheter comprising a catheter tube and a balloon portion having a non-linear compliance curve within its useful range as an angioplasty balloon, the balloon portion of the catheter having inner and outer balloons having unequal low pressure diameters enveloped one within the other and having a greater uninflated circumference than the circumference of the catheter tube, one of said balloons being made of compliant material and the other being made of non-compliant material, comprising the steps of:

(a) pressurizing the inner balloon to a first inflation pressure to inflate the balloon made of compliant material beyond its low pressure diameter such that the balloon section of the catheter increases in diameter, in response to this step, to a first predetermined diameter along the compliance curve of the compliant material which corresponds to said first inflation pressure, and then

(b) increasing the pressure supplied to the inner balloon to a second inflation pressure sufficient to inflate the balloon made of non-compliant material beyond its low pressure diameter such that the balloon section of the catheter increases in diameter, in response to this step, to a second predetermined diameter along the compliance curve of the non-compliant material which corresponds to said second inflation pressure.

17. A method of using a balloon catheter having a non-linear compliance curve as set forth in claim 16, wherein the outer balloon is the compliant balloon and the inner balloon is the non-compliant balloon.

18. The method as set forth in claim 16 wherein the balloon made of a compliant plastic material is made of a thermoplastic polymer.

19. The method as set forth in claim 16 wherein the balloon made of a compliant plastic material is made of a material selected from the group consisting of polyethylene, polyethylene blends, polyethylene copolymers, ionomers, polyesters, polyurethanes, polycarbonates, polyamides, polyvinyl chloride, acrylonitrile-butadiene-styrene copolymers, polyether-polyester copolymers, and polyether-polyamide copolymers.

20. The method as set forth in claim 16 wherein the balloon made of a compliant material has a compliance curve which has a slope corresponding to an increase in diameter of between 15% and 40% when expanded from said first low pressure diameter at 2 atmospheres pressure to an expanded diameter at 6 atmospheres pressure.

21. The method as set forth in claim 16 wherein the balloon made of a compliant material has a compliance curve which has a slope corresponding to an increase in diameter of between 15% and 40% when expanded from said first low pressure diameter at 2 atmospheres pressure to an expanded diameter at 12 atmospheres pressure.

22. The method of claim 16 wherein the compliance curve of the balloon portion of the catheter has a segment which corresponds substantially to a segment of the compliance curve of the balloon made of a compliant material and which has a slope corresponding to an increase in diameter of no more than 10% per atmosphere of increased pressure.

23. The invention as set forth in claim 16 wherein the balloon made of a complaint plastic material is made of a thermoplastic elastomer.

24. A method of using an angioplasty balloon catheter, the catheter comprising a balloon portion having a non-linear compliance curve within its useful range as an angioplasty balloon, the balloon portion of the catheter having inner and outer balloons having unequal low pressure diameters enveloped one within the other, one of said balloons being made of compliant material and the other being made of non-compliant material, comprising the steps of:

(a) pressurizing the inner balloon to a first inflation pressure to inflate the balloon made of compliant material beyond its low pressure diameter such that the balloon section of the catheter increases in diameter in response to this step, to a first predetermined diameter along the compliance curve of the compliant material which corresponds to said first inflation pressure, and then

(b) increasing the pressure supplied to the inner balloon to a second inflation pressure sufficient to inflate the balloon made of non-compliant material beyond its low pressure diameter such that the balloon section of the catheter increases in diameter, in response to this step, to a second predetermined diameter along the compliance curve of the non-compliant material which corresponds to said second inflation pressure; and

(c) wherein the balloon made of a compliant plastic material, is the inner balloon and the balloon made of non-compliant plastic material, is the outer balloon.

25. A method of dilating a restricted zone in a blood vessel using a balloon catheter including a catheter tube comprising the steps of:

(a) locating an uninflated balloon portion of the balloon catheter in a blood vessel such that the uninflated balloon portion crosses the restricted zone, the balloon portion having an uninflated circumference greater than the circumference of the catheter tube and a non-linear compliance curve including high compliance and low compliance portions within the useable range of the balloon portion as a dilation element for said vessel;

(b) metering inflation fluid to the ;

interior of the balloon portion, causing the diameter of the balloon to increase to a desired diameter along the high compliance portion of the curve;

(c) increasing the pressure being applied to the inflation fluid being metered to the interior of the balloon portion such that further increase in the balloon diameter above the desired diameter will follow the low compliance portion of the curve.

26. A method of dilating a restricted zone in a blood vessel with a balloon catheter having a balloon inflation portion including a non-compliant inner balloon within a compliant outer balloon comprising the steps of:

(a) locating the balloon inflation portion of the balloon catheter in a blood vessel such that the balloon inflation portion crosses the restricted zone;

(b) metering inflation fluid to the interior of the inner balloon at controlled pressures, causing the diameter of the balloon inflation portion to increase to a desired diameter along the compliance curve of the inner balloon;

(c) increasing the metering of inflation fluid to the interior of the inner balloon such that the inner balloon is ruptured and the inflation fluid is brought into communication with the outer balloon,

(d) further metering inflation fluid to the outer balloon such that the diameter of the balloon inflation portion increases following the compliance curve of the outer compliant balloon.

27. A method of dilating one or more restricted zones in a blood vessel using a catheter having a catheter tube and a balloon dilating element located at the distal end of the catheter, the dilating element having a non-linear compliance curve, the compliance curve having first and second segments of different slope providing available inflated diameters for said dilating element, one of said segments being a compliant segment and the other being a non-compliant segment, the method comprising:

(a) locating the uninflated balloon dilating element across a restricted zone in a blood vessel, the uninflated balloon dilating element having greater circumference than the catheter tube circumference;

(b) selecting a first inflated diameter from the diameters available along said first segment and a first pressure corresponding to said first diameter on said non-linear compliance curve;

(c) pressurizing the dilating element to the selected first pressure so as to dilate the restricted zone then crossed by the dilating element;

(d) selecting a second inflated diameter from the diameters available along the second of said segments and a second pressure corresponding to said diameter on said non-linear compliance curve; and

(e) pressurizing the dilating element to the second pressure while the balloon is located across the same or a different restricted zone so as to dilate the restricted zone then crossed by the dilating element.

28. The method of claim 27 wherein said pressurizing steps (c) and (e) are conducted while the dilating element is located across the same restricted zone.

29. The method of claim 27 wherein said first segment is a compliant curve segment and said second segment is a non-compliant curve segment.

30. The method of claim 27 wherein the diameters available on said first segment are higher than the diameters available on said second segment.

31. A method of dilating one or more restricted zones in a blood vessel using a catheter having a balloon dilating element located at the distal end of the catheter, the dilating element having a non-linear compliance curve, the compliance curve having first and second segments of different slope providing available inflated diameters for said dilating element, one of said segments being a compliant segment and the other being a non-compliant segment, the method comprising:

(a) locating the uninflated balloon dilating element across a restricted zone in a blood vessel;

(b) selecting a first inflated diameter from the diameters available along said first segment and a first pressure corresponding to said first diameter on said non-linear compliance curve;

(c) pressurizing the dilating element to the selected first pressure so as to dilate the restricted zone then crossed by the dilating element;

(d) selecting a second inflated diameter from the diameters available along the second of said segments and a second pressure corresponding to said diameter on said non-linear compliance curve; and

(e) pressurizing the dilating element to the second pressure while the balloon is located across the same or a different restricted zone so as to dilate the restricted zone then crossed by the dilating element; and

(f) wherein between said pressurizing steps (c) and (e), the balloon is relocated across a different restricted zone.

32. A method of dilating one or more restricted zones in a blood vessel using a catheter having a balloon dilating element located at the distal end of the catheter, the dilating element having a non-linear compliance curve, the compliance curve having first and second segments of different slope providing available inflated diameters for said dilating element, one of said segments being a compliant segment and the other being a non-compliant segment, the method comprising;

(a) locating the uninflated balloon dilating element across a restricted zone in a blood vessel;

(b) selecting a first inflated diameter from the diameters available along said first segment and a first pressure corresponding to said first diameter on said non-linear compliance curve;

(c) pressurizing the dilating element to the selected first pressure so as to dilate the restricted zone then crossed by the dilating element;

(d) selecting a second inflated diameter from the diameters available along the second of said segments and a second pressure corresponding to said diameter on said non-linear compliance curve; and

(e) pressurizing the dilating element to the second pressure while the balloon is located across the same or a different restricted zone so as to dilate the restricted zone then crossed by the dilating element; and

(f) said first segment is a non-compliant curve segment and said second segment is a compliant curve segment.