System and method of use for revascularizing stenotic bypass grafts and other occluded blood vessels

• US 6,080,170 A
• Filed: 01/19/1999
• Issued: 06/27/2000
• Est. Priority Date: 07/26/1996
• Status: Expired due to Term

• Current Assignee: Kensey Nash Corporation (DSM-Firmenich AG)
• Original Assignee: Kensey Nash Corporation (DSM-Firmenich AG)
• Inventors: Nash, John E., Fisher, William T., Dodson, Charles W. Jr.
• Primary Examiner(s): Buiz, Michael
• Assistant Examiner(s): TRUONG, KEVIN THAO
• Application Number:
  US09/233,712
• Time in Patent Office: 525 Days
• Field of Search: 606/159, 606/170, 606/167, 606/180, 604/22, 128/898
• US Class Current: 606/159
• CPC Class Codes: A61B 17/22 Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for dilators A61M29/00
• CPC Class Codes: A61B 17/3203 Fluid jet cutting instruments
• CPC Class Codes: A61B 17/32037 for removing obstructions from inner organs or blood vessels, e.g. for atherectomy
• CPC Class Codes: A61B 17/320758 with a rotating cutting instrument, e.g. motor driven A61B17/320725, A61B17/32075 and A61B17/320783 take precedence; for removing intra-ocular material A61F9/00763; endoscopic rotatable cutting instruments A61B17/32002
• CPC Class Codes: A61B 2017/22048 Balloons
• CPC Class Codes: A61B 2017/22067 Blocking; Occlusion A61B2017/22054 takes precedence
• CPC Class Codes: A61B 2017/320775 Morcellators, impeller or propeller like means
• CPC Class Codes: A61B 2217/005 with suction drainage system
• CPC Class Codes: A61B 2217/007 with irrigation system
• CPC Class Codes: A61M 1/77 Suction-irrigation systems aspiration tips supplying fluids A61M1/85; specific for negative pressure wound therapy A61M1/92; combined with tracheal tubes A61M16/0463
• CPC Class Codes: A61M 1/85 with gas or fluid supply means, e.g. for supplying rinsing fluids or anticoagulants for negative pressure wound therapy A61M1/92, A61M1/94; combined with tracheal tubes A61M16/0463; dental instruments with combined rinsing and aspirating A61C17/0208
• CPC Class Codes: A61M 2025/1095 with perfusion means for enabling blood circulation while the balloon is in an inflated state or in a deflated state, e.g. permanent by-pass within catheter shaft
• CPC Class Codes: A61M 2205/05 combined with other kinds of therapy
• CPC Class Codes: A61M 5/14232 Roller pumps

Abstract

A system and method for opening a lumen in an occluded blood vessel, e.g., a coronary bypass graft, of a living being. The system comprises an atherectomy catheter having a working head, e.g., a rotary impacting impeller, and a debris extraction sub-system. The atherectomy catheter is located within a guide catheter. The working head is arranged to operate on, e.g., impact, the occlusive material in the occluded vessel to open a lumen therein, whereupon some debris may be produced. The debris extraction sub-system introduces an infusate liquid at a first flow rate adjacent the working head and withdraws that liquid and some blood at a second and higher flow rate, through the guide catheter to create a differential flow adjacent the working head, whereupon the debris is withdrawn in the infusate liquid and blood for collection outside the being'"'"'s body. The introduction of the infusate liquid may also be used to establish an unbalanced flow adjacent the working head to enable the atherectomy catheter to be steered hydrodynamically. A guide wire having an inflatable balloon on its distal end may be used with the atherectomy catheter to block the flow of debris distally, while enabling distal tissues to be perfused with an oxygenating liquid. At least one flow control port may be provided in the guide catheter to prevent collapse of the vessel being revascularized. A cradle is provided to fix the guide catheter and guide wire in position within the body of the being while enabling the atherectomy catheter to be advanced along the guide wire and through the guide catheter.

Claims

1. An intravascular system for opening a lumen in a portion of an occluded blood vessel of a living being'"'"'s vascular system, the occluded blood vessel portion being occluded by an occlusive material and being located downstream of a patent blood vessel portion, said system comprising a first catheter, a vessel-opening catheter, a debris blocking member, and a debris extraction system, said first catheter having a distal end portion including an opening, a passageway extending therethrough and in communication with said opening, and at least one blood entrance port, said vessel-opening catheter extending through said first catheter and having a working head, said working head being arranged to be located immediately adjacent the occlusive material for operating on the occlusive material to open a lumen for the freer flow of blood therethrough, whereupon some debris may be produced, said debris blocking member being located distally of said working head to prevent debris from flowing distally thereof, said debris extraction system being operative to introduce a liquid adjacent said working head and to cause debris and said liquid to flow proximally through said opening and said passageway for extraction, said at least one blood entrance port of said first catheter being in communication with said passageway and with the patent blood vessel portion, whereupon blood from said patent blood vessel portion may enter for merger with said liquid and the debris.

2. The intravascular system of claim 1 wherein said debris extraction system introduces said liquid at a first flow rate adjacent said working head and withdraws said liquid through said passageway at a second and higher flow rate to create a differential flow adjacent said working head, whereupon the debris is withdrawn by said differential flow and flows with said liquid proximally through said passageway for extraction.

3. The intravascular system of claim 1 wherein said blood entrance port comprises at least one opening in said first catheter located proximally of said distal end portion.

4. The intravascular system of claim 1 wherein said first catheter includes an open distal end and wherein said open distal end forms said blood entrance port.

5. The intravascular system of claim 1 wherein said system is configured so that the pressure within the area contiguous with said working head is sufficient to prevent collapse of the vessel.

6. The intravascular system of claim 5 wherein said pressure is at least venous pressure.

7. The intravascular system of claim 1 wherein said working head comprises a movable impacting member.

8. The intravascular system of claim 1 wherein said working head is rotatable.

9. The intravascular system of claim 1 wherein said working head delivers a stent in the lumen of the vessel.

10. The intravascular system of claim 1 wherein said passageway has a predetermined cross sectional area, and wherein the area of said port is established by the solution to the following two equations:

##EQU3## Where;

Q1+Q2+Q3=flow in³ /sec;

D1=Guide catheter inner diameter (inches);

D2=Working catheter outer diameter (inches);

L=Guide catheter length (inches);

P2=vessel pressure (psi);

P3=vacuum source pressure (psi);

e=eccentricity factor, D1 rel. to D2.

Equation (2);

space="preserve" listing-type="equation">Q2=90,950.0·

Ab·

(P1-P2).sup.0.5

Where

Q2=flow mL/min

Ab=bypass port area in²

P1=aorta (or upstream patent vessel) pressure psi.

P2=vessel pressure psi.

11. The intravascular system of claim 1 wherein said debris blocking member comprises a balloon.

12. The intravascular system of claim 11 wherein said balloon is disposed on an elongated flexible guide member, and wherein said vessel-opening catheter is extendable along said elongated flexible guide member to a position proximally of said debris blocking member.

13. The intravascular system of claim 12 additionally comprising a stop disposed on said elongated flexible member proximally of said balloon to prevent the extension of said working head into engagement with said balloon.

14. The intravascular system of claim 1 wherein said debris extraction system introduces said infusate liquid at a first flow rate adjacent said working head and withdraws said liquid through said passageway at a second and higher flow rate to create a differential flow adjacent said working head, whereupon the debris is withdrawn by said differential flow and flows with said liquid proximally through said passageway for extraction.

15. The intravascular system of claim 14 wherein the first and second flow rates are correlated to each other.

16. The intravascular system of claim 15 wherein said first and second flow rates are adjustable.

17. The intravascular system of claim 1 wherein said vessel-opening catheter includes a rotatable flexible, helical member, said helical member being operative to pump the liquid through said vessel-opening catheter to a position adjacent said working head.

18. The intravascular system of claim 17 wherein said working head is rotary member and wherein said flexible helical member is connected to said working head to effect the rotation of the working head.

19. The intravascular system of claim 1 wherein said working head is arranged to be advanced through said first catheter to effect the opening of the lumen in a portion of the occluded blood vessel.

20. The intravascular system of claim 19 additionally comprising an elongated flexible guide member, said vessel-opening catheter being arranged to be extended over said elongated flexible guide member, said elongated flexible guide member being arranged to be extended through said first catheter.

21. The intravascular system of claim 20 wherein said vessel-opening catheter is an atherectomy catheter, said atherectomy catheter having a distal portion extending through said first catheter and a proximal portion having a turbine for effecting the high speed rotation of said working head, and additionally comprising a device for holding said first catheter and said flexible guide member relative to each other, said device supporting said turbine of said atherectomy catheter to enable said turbine to be advanced with respect to said device so that said distal portion of said atherectomy catheter is advanced through said first catheter.

22. The intravascular system of claim 21 wherein said device is arranged for holding said first catheter and said guide member at a fixed position with respect to the vascular system of the being.

23. The intravascular system of claim 1 additionally comprising an elongated flexible guide member over which said vessel-opening catheter is arranged to be extended, said elongated flexible guide member extending through said first catheter.

24. The intravascular system of claim 23 additionally comprising a device arranged for holding said first catheter and said elongated flexible guide member relative to each other.

25. The intravascular system of claim 24 wherein said device is arranged for holding a portion of said vessel-opening catheter to enable said vessel-opening catheter to be moved with respect to said first catheter and said elongated flexible guide member.

26. The intravascular system of claim 23 additionally comprising a device arranged for holding said first catheter and said elongated flexible guide member relative to the vascular system of the being.

27. The intravascular system of claim 23 wherein said debris blocking member is mounted on said elongated flexible guide member.

28. The intravascular system of claim 27 wherein said debris blocking member comprises an inflatable balloon.

29. The intravascular system of claim 28 additionally comprising a stop member mounted on said elongated flexible guide member proximally of said balloon.

30. The intravascular system of claim 1 wherein said vessel-opening catheter includes a helical rotary drive member located within the interior thereof for effecting the operation of said working head, said drive member being arranged to operate as a Archimedes pump to carry said liquid to a position adjacent said working head.

31. The intravascular system of claim 30 wherein said helical rotary drive member includes a distal end portion having plural helices closely spaced with respect to one another, and a proximal end portion having plural helices less closely spaced with respect to one another than the helices of the distal end portion.

32. The intravascular system of claim 30 wherein said system includes an infusate pump for delivering the liquid into the interior of the vessel-opening catheter and into fluid communication with said helical rotary drive member.

33. The intravascular system of claim 32 wherein said infusate pump is a peristaltic pump.

34. The intravascular system of claim 33 wherein said peristaltic pump includes soft tubing.

35. A method for opening a lumen in a portion of an occluded blood vessel of a living being'"'"'s vascular system, the occluded blood vessel portion being occluded by an occlusive material, the occluded blood vessel portion being located distally of a patent blood vessel portion, said method comprising:

(a) extending a first catheter through said patent blood vessel portion into said occluded blood vessel portion, said first catheter having a distal end portion and a port located proximally of said distal end portion;

(b) blocking the flow of blood and debris distally of a working head;

(c) providing a vessel-opening catheter having said working head and extending said vessel-opening catheter through said first catheter so that said working head is located in the occluded blood vessel portion, said first catheter and said vessel-opening catheter defining a passageway therebetween;

(d) operating said working head to open the occluded blood vessel portion for the freer flow of blood therethrough;

(e) introducing a liquid at a first flow rate adjacent said working head and withdrawing said liquid at a second and higher flow rate to create a differential flow adjacent said working head, whereupon blocked debris is withdrawn with said liquid for passage proximally through said passageway; and

(g) providing a path for blood within said patent blood vessel portion to flow into said passageway for merger with said liquid and debris.

36. The method of claim 35 additionally comprising introducing a stent into the occluded blood vessel portion.

37. The method of claim 36 wherein said occluded blood vessel portion comprises a bypass graft.

38. A method for opening a lumen in a portion of an occluded blood vessel of a living being'"'"'s vascular system, the occluded blood vessel portion being occluded by an occlusive material, the occluded blood vessel portion being located distally of a patent blood vessel portion, said method comprising:

(a) extending a first catheter through said patent blood vessel portion into said occluded blood vessel portion, said first catheter having a distal end portion and a port located proximally of said distal end portion;

(b) extending a second catheter through said first catheter so that a working portion of said second catheter is located in the occluded blood vessel portion;

(c) blocking the occluded blood vessel portion distally of said working portion of said second catheter;

(d) using said second catheter to open a lumen in the occluded portion of the blood vessel for the freer flow of blood therethrough;

(e) introducing a liquid into said occluded blood vessel portion and withdrawing said liquid and any debris produced by the opening of the occluded portion of the blood vessel through a passageway in said first catheter; and

(g) providing a path for blood from the patent blood vessel portion to flow through said port into said passageway for merger with said liquid and debris.

39. The method of claim 38 wherein the path provided for the blood from the patent blood vessel portion ensures that the pressure within the occluded blood vessel portion is sufficient to prevent it from collapsing.

40. The method of claim 39 wherein said pressure is at least equal to venous pressure.

41. The method of claim 38 wherein said second catheter comprises a rotary working head arranged to operate on the material forming the restriction to form the lumen therein.

42. The method of claim 38 additionally comprising the step of:

(h) introducing a third catheter through said first catheter, said third catheter being arranged to carry a stent into the lumen formed in the occluded blood vessel to hold said lumen open.

43. The method of claim 38 wherein said second catheter is arranged to carry a stent into the occluded blood vessel to open a lumen in the material forming the restriction.

44. The method of claim 43 additionally comprising the steps of:

(h) extending a third catheter through said first catheter, said third catheter being arranged for introducing said liquid into said occluded blood vessel portion.