Atherectomy catheter

Abstract

An atherectomy catheter includes an outer tube; an inner tube which is inserted into the outer tube rotatably about an axis thereof and axially movably; a removing member fixed to a distal portion of the inner tube and accommodated in the outer tube to drill and remove an occlusive material which stenoses or occludes a lumen of a blood vessel; and a guide member mounted on the inner tube in penetration therethrough so that the guide member functions as the axis of the inner tube when the inner tube rotates. The removing member has a developed state in which a distal end of the removing member unfolds when the removing member is projected from a distal portion of the outer tube and radially expands owing to an elastic restoring force thereof, and the removing member can drill said occlusive material in the developed state by rotating about the guide member functioning as an axis of said removing member and moving the removing member toward a distal end of the atherectomy catheter.

Description

Claims

1. An atherectomy catheter comprising: a flexible outer tube;a flexible inner tube which is inserted into said outer tube rotatably about an axis thereof and axially movably;a removing member fixed to a distal portion of said inner tube and accommodated in said outer tube to drill and remove an occlusive material which stenoses or occludes a lumen of a tubular organ; anda guide member, flexible and long, which penetrates said inner tube so that said guide member functions as said axis of said inner tube when said inner tube rotates,wherein said removing member has a developed state in which a distal end of said removing member unfolds when said removing member is projected from a distal portion of said outer tube and radially expands owing to an elastic restoring force thereof, and said removing member can drill said occlusive material in said developed state by rotating said removing member about said guide member functioning as an axis of said removing member and moving said removing member toward a distal end of said atherectomy catheter.

2. An atherectomy catheter according to claim 1, wherein said removing member is thin and approximately cylindrical and has a plurality of projected portions projected toward a distal end of said atherectomy catheter at said distal portion thereof, with said projected portions circumferentially disposed.

3. An atherectomy catheter according to claim 1, wherein said removing member has a plurality of open portions having an area of 4 to 97% of an area of a side surface thereof in said developed state.

4. An atherectomy catheter according to claim 1, wherein said removing member is reticulate.

5. An atherectomy catheter according to claim 1, wherein in said developed state, said distal portion of said removing member moves away from said guide member.

6. An atherectomy catheter according to claim 1, wherein at least one part of said removing member is composed of a shape memory alloy.

7. An atherectomy catheter according to claim 1, further comprising a first fixing means for preventing an axial movement of said inner tube with respect to said outer tube.

8. An atherectomy catheter according to claim 7, wherein when an axial movement of said inner tube is fixed, said first fixing means has a function of permitting a rotation of said inner tube about an axis thereof with respect to said outer tube and interrupting a passage of a fluid through a first passage formed between an inner periphery of said outer tube and a periphery of said inner tube.

9. An atherectomy catheter according to claim 1, wherein a connector having a port communicating with a first passage formed on an inner periphery of said outer tube and a periphery of said inner tube is provided at a proximal portion of said outer tube.

10. An atherectomy catheter according to claim 7, wherein a connector having a port communicating with a first passage formed on an inner periphery of said outer tube and a periphery of said inner tube is provided at said proximal portion of said outer tube; and said first fixing means is provided on said connector.

11. An atherectomy catheter according to claim 10, wherein said first fixing means comprises a valve mounted at an inner side of a proximal portion of said connector and an operation portion pressing said valve toward said inner tube or releasing said valve from a state in which said valve is pressed.

12. An atherectomy catheter according to claim 1, wherein said inner tube has at a proximal portion thereof a rotation-assisting means for making a rotation torque transmitting performance at said proximal portion thereof larger than a rotation torque transmitting performance at a distal portion thereof.

13. An atherectomy catheter according to claim 1, further comprising a convex portion formed on a periphery of said distal portion of said inner tube and a tubular member into which said distal portion of said inner tube is inserted; said distal portion of said inner tube is inserted into said tubular member with said tubular member disposed nearer to a proximal side of said atherectomy catheter than said convex portion formed on said inner tube; and said tubular member is fixed to said periphery of said inner tube with a proximal portion of said removing member disposed between said periphery of said inner tube and an inner periphery of said tubular member, whereby said removing member is fixed to said inner tube.

14. An atherectomy catheter according to claim 1, wherein said guide member is removably mounted on said inner tube and said atherectomy catheter further comprises a second fixing means for fixing said guide member to said inner tube.

15. An atherectomy catheter according to claim 14, wherein said second fixing means has a hub provided at said proximal portion of said inner tube and a hub, provided at a proximal portion of said guide member, which is fittable on said hub provided on said inner tube.

16. An atherectomy catheter according to claim 15, wherein when a hub provided on said inner tube fits on a hub provided on said guide member, a distal side of said guide member projects 1 to 8 mm from a distal end of said removing member.

17. An atherectomy catheter according to claim 14, wherein said inner tube is connectable with a rotation-assisting device for rotating said inner tube and said removing member.

18. An atherectomy catheter according to claim 17, wherein said rotation-assisting device is connectable with said hub provided on said guide member.

19. An atherectomy catheter according to claim 1, wherein said guide member is composed of super-elastic alloy, stainless steel or resin.

20. An atherectomy catheter according to claim 1, wherein said distal portion of said guide member is composed essentially of an X-ray opaque material or provided with an X-ray opaque portion.

21. An atherectomy catheter according to claim 1, wherein said guide member has a distal tapered portion whose outer diameter gradually decreases to a distal end thereof; and a distal end of said tapered portion is rounded.

22. An atherectomy catheter according to claim 1, wherein said outer tube has an inner layer, an intermediate layer, and an outer layer; said intermediate layer functions as a reinforcing material; and said inner layer is composed of a low-frictional material.

23. An atherectomy catheter according to claim 22, wherein said intermediate layer is composed of metal wires or carbon fibers; and said inner layer is composed of fluorinated resin.

24. An atherectomy catheter according to claim 1, further comprising an X-ray opaque portion provided to said distal portion of said outer tube.

25. An atherectomy catheter according to claim 1, wherein a fluid containing said occlusive material drilled by said removing member can be discharged outside a human body through said first passage formed between said inner periphery of said outer tube and said periphery of said inner tube.

26. An atherectomy catheter according to claim 25, wherein a fluid can be injected into a tubular organ through a second passage, a part of which is formed of a lumen of said inner tube.

27. An atherectomy catheter according to claim 26, further comprising an injection and discharge means for discharging a fluid through said first passage, adjusting a flow rate of said fluid, injecting a fluid into said tubular organ through said second passage, and adjusting a flow rate of said fluid.

28. An atherectomy catheter comprising: a flexible outer tube;a flexible inner tube which is inserted into said outer tube rotatably about an axis thereof and axially movably;first and second removing members fixed to a distal portion of said inner tube and accommodated in said outer tube to drill and remove an occlusive material which stenoses or occludes a lumen of a tubular organ,wherein said first and second removing members project from a distal portion of said outer tube and radially expand, thus having a developed state in which a distal end of each of said first and second removing members unfolds.

29. An atherectomy catheter according to claim 28, wherein said first removing member is thin and approximately cylindrical and has a plurality of projected portions projected toward a distal end of said atherectomy catheter at said distal portion thereof, with said projected portions circumferentially disposed; and said second removing member is thin and approximately cylindrical and has a plurality of projected portions projected toward a distal end of said catheter at said distal portion thereof, with said projected portions circumferentially disposed.

30. An atherectomy catheter according to claim 28, wherein said first and second removing members are concentric with said axis of said inner tube; and said first removing member is disposed inward from said second removing member.

31. An atherectomy catheter according to claim 30, wherein in said developed state, said distal end of said first removing member projects from said distal end of said second removing member.

32. An atherectomy catheter according to claim 28, wherein in said developed state, an outer diameter at said distal portion of said first removing member or/and an outer diameter at said distal portion of said second removing member gradually decreases to said distal end thereof.

33. An atherectomy catheter according to claim 28, further comprising a fixing means for preventing an axial movement of said inner tube with respect to said outer tube.

34. An atherectomy catheter according to claim 33, wherein when an axial movement of said inner tube is fixed, said fixing means has a function of permitting a rotation of said inner tube about an axis thereof with respect to said outer tube and interrupting a passage of a fluid through a first passage formed between an inner periphery of said outer tube and a periphery of said inner tube.

35. An atherectomy catheter according to claim 28, wherein said inner tube has at a proximal portion thereof a rotation-assisting means for making a rotation torque transmitting performance at said proximal portion thereof larger than a rotation torque transmitting performance at a distal portion thereof.

36. An atherectomy catheter according to claim 28, further comprising first and second convex portions formed on a periphery of said distal portion of said inner tube and first and second tubular members into which said distal portion of said inner tube is inserted, wherein said distal portion of said inner tube is inserted into said first tubular member with said first tubular member disposed nearer to a proximal side of said atherectomy catheter than said first convex portion formed on said inner tube, and said first tubular member is fixed to said periphery of said inner tube with a proximal portion of said first removing member disposed between said periphery of said inner tube and an inner periphery of said first tubular member, whereby said first removing member is fixed to said inner tube; andsaid distal portion of said inner tube is inserted into said second tubular member with said second tubular member disposed nearer to a proximal side of said atherectomy catheter than said second convex portion formed on said inner tube, and said second tubular member is fixed to said periphery of said inner tube with a proximal portion of said second removing member disposed between said periphery of said inner tube and an inner periphery of said second tubular member, whereby said second removing member is fixed to said inner tube.

37. An atherectomy catheter according to claim 28, further comprising a flexible and long guide member, removably mounted on said inner tube in penetration therethrough, which functions as an axis of said inner tube when said inner tube rotates.

38. An atherectomy catheter according to claim 37, wherein said guide member has a hub, provided at a proximal portion thereof, which is fitting on a hub provided at a proximal portion of said inner tube.

39. An atherectomy catheter according to claim 37, wherein a hub is provided at said proximal portion of said guide member; and a rotation-assisting device for rotating said inner tube and said first and second removing members is connectable with said hub.

40. An atherectomy catheter according to claim 28, wherein a fluid containing said occlusive material drilled by said first and second removing members can be discharged outside a human body through a first passage formed between said inner periphery of said outer tube and said periphery of said inner tube.

41. An atherectomy catheter according to claim 40, wherein a fluid can be injected into a tubular organ through a second passage, a part of which is formed of a lumen of said inner tube.

42. An atherectomy catheter according to claim 41, further comprising an injection and discharge means for discharging a fluid through said first passage, adjusting a flow rate of said fluid, injecting a fluid into said tubular organ through said second passage, and adjusting a flow rate of said fluid.