METHODS AND DEVICES FOR CUTTING TISSUE

• US 20110130777A1
• Filed: 12/02/2010
• Published: 06/02/2011
• Est. Priority Date: 12/02/2009
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Foxhollow Technologies Incorporated (Medtronic Plc)
• Inventors: VanPelt, Robert Wayne JR., Guggenheimer, Ethan Andrew, Zhang, Zhiyong, Moberg, John Robert, Whealon, William Joseph, Rangwala, Hussain S.
• Granted Patent: US 8,496,677 B2
• Time in Patent Office: Days
• US Class Current: 606/159
• 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 17/320783 through side-hole, e.g. sliding or rotating cutter inside catheter
• CPC Class Codes: A61B 2017/320775 Morcellators, impeller or propeller like means
• CPC Class Codes: A61B 2017/320791 with cutter extending outside the cutting window

Abstract

A catheter which includes a cutting element having one or more raised elements is provided. The cutting element has a cup-shaped surface at the distal end that may be smooth and continuous except for the raised elements. The raised elements have a surface that tends to direct cut particles of material towards one or more of the axis of rotation of the cutting element, the catheter axis, or a particle collection chamber. In further aspects of the invention, a cutting element oscillates in a direction roughly parallel to the axis of rotation of the cutting element.

Claims

1. An atherectomy catheter comprising:

a body having an opening;

a rotatable shaft coupled to the body;

a tissue collection chamber coupled to the body and positioned distal to the cutting element;

a cutting element coupled to the rotatable shaft for rotating the cutting element about an axis of rotation, the cutting element having a cup-shaped surface and a cutting edge, the cup-shaped surface being configured to re-direct tissue cut by the cutting edge in a distal direction when the cup-shaped surface moves in the distal direction; and

a raised element extending outwardly from the cup-shaped surface of the cutting element, the raised element being configured to direct cut particles of material towards one of more of the axis of rotation of the cutting element, a catheter longitudinal axis, or the tissue collection chamber.

2. The atherectomy catheter of claim 1, wherein the raised element is configured to direct cut particles of material towards the axis of rotation of the cutting element.

3. The atherectomy catheter of claim 2, wherein the cutting edge is at a radially outer edge of the cutting element.

4. The atherectomy catheter of claim 3, wherein the raised element comprises a curved raised element cutting edge.

5. The atherectomy catheter of claim 4, wherein the raised element comprises a first wall that extends from the curved raised element cutting edge to the cup-shaped surface, the first wall directing the cut particles of material towards the axis of rotation of the cutting element.

6. The atherectomy catheter of claim 5, wherein the first wall curves from a relatively tangential angle with the cutting edge at the radially outer edge of the cutting element to a relatively radial angle closer to the axis of rotation of the cutting element.

7. The atherectomy catheter of claim 6, wherein the raised element comprises a distal wall that extends from the first, curved raised element cutting edge to a second edge, the distal wall forming an angle of less than 90 degrees with respect to the axis of rotation of the cutting element.

8. The atherectomy catheter of claim 7, wherein the first, curved raised element cutting edge is more distal than the second edge.

9. The atherectomy catheter of claim 8, wherein the minimum radial distance between the first, curved raised element cutting edge and the cutting edge of the cutting element is less than the minimum radial distance between the second edge and the cutting edge of the cutting element.

10. The atherectomy catheter of claim 7, wherein an included angle between the first wall and the distal wall is an obtuse angle.

11. The atherectomy catheter of claim 3, wherein the raised element is recessed proximally from the cutting edge by a longitudinal distance.

12. The atherectomy catheter of claim 11, wherein the raised element is recessed proximally from the cutting edge by a longitudinal distance of 0.0010 to 0.0050 inch (0.0025 to 0.0127 cm).

13. The atherectomy catheter of claim 3, wherein the raised element is recessed from the cutting edge by a radial distance of 0.0010 to 0.0050 inch (0.0025 to 0.0127 cm).

14. The atherectomy catheter of claim 2, wherein the raised element comprises a first wall that extends from a raised element cutting edge to the cup-shaped surface, the first wall directing the cut particles of material towards the axis of rotation of the cutting element and wherein the first wall forms an acute angle with the cup-shaped surface to form an undercut.

15. The atherectomy catheter of claim 14, wherein the raised element comprises a distal wall that extends from the first raised element cutting edge to a second edge, the distal wall forming an angle of less than 90 degrees with respect to the axis of rotation of the cutting element.

16. The atherectomy catheter of claim 15, wherein the first raised element cutting edge is more distal than the second edge.

17. The atherectomy catheter of claim 16, wherein the minimum radial distance between the first raised element cutting edge and the cutting edge of the cutting element is less than the minimum radial distance between the second edge and the cutting edge of the cutting element.

18. The atherectomy catheter of claim 15, wherein a wall having a rake angle is interspersed between the intersection of the first wall and the distal wall.

19. The atherectomy catheter of claim 18, wherein the rake angle is negative.

20. The atherectomy catheter of claim 1, wherein the cup-shaped surface of the cutting element is smooth and uninterrupted throughout at least 300 degrees when viewed along the axis of rotation of the cutting element.

21. The atherectomy catheter of claim 1, wherein the cup-shaped surface of the cutting element is smooth and uninterrupted for at least 90% of the surface area of the cutting element when viewed along the axis of rotation of the cutting element.

22. The atherectomy catheter of claim 1, wherein the cup-shaped surface of the cutting element has an outer radius when viewed along the axis of rotation of the cutting element, the cup-shaped surface being continuous and uninterrupted from the axis of rotation to at least half the distance to the outer radius.

23. The atherectomy catheter of claim 1, further comprising a plurality of raised elements, the plurality of raised elements altogether occupying an area less than 60 degrees and less than 5% of the surface area when viewed along the axis of rotation of the cutting element, and the cup-shaped surface being smooth and uninterrupted for at least 90% of the surface area.

24. The atherectomy catheter of claim 1, wherein a plurality of raised elements extend outwardly from the cup-shaped surface, the plurality of raised elements being 1, 2, 3, 4, 6, or 8 raised elements.

25. The atherectomy catheter of claim 1, wherein the cutting element is movable between a stored position and a cutting position relative to the opening.

26. The atherectomy catheter of claim 25, wherein the cutting element is moved between the stored position and the cutting position by sliding the cutting element against a cam surface.

27. The atherectomy catheter of claim 26, wherein a distal portion of the catheter relative to a proximal portion is deflected by sliding the cutting element against the cam surface.

28. The atherectomy catheter of claim 1, wherein the cutting element is configured to oscillate in a direction substantially parallel to the axis of rotation of the cutting element

29. An atherectomy catheter comprising:

a body having an opening;

a rotatable shaft coupled to the body;

a tissue collection chamber coupled to the body and positioned distal to the cutting element; and

a cutting element coupled to the rotatable shaft for rotating the cutting element about an axis of rotation, the cutting element having a cutting edge, and the cutting element being configured to oscillate in a direction substantially parallel to the axis of rotation of the cutting element.

30. The atherectomy catheter of claim 29, wherein the atherectomy catheter comprises a ramp having one or more recesses, the cutting element comprises one or more raised portions on a cam surface of the cutting element, the one or more raised portions fitting within the one or more recesses when the raised portions and the recesses are aligned, and the raised portions leaving and entering the recesses as the cutting element is rotated and thereby causing the cutting element to oscillate.

31. The atherectomy catheter of claim 29, wherein the atherectomy catheter comprises a ramp having one or more raised portions, the cutting element comprises one or more recesses on a cam surface of the cutting element, the one or more raised portions fitting within the one or more recesses when the raised portions and the recesses are aligned, and the raised portions leaving and entering the recesses as the cutting element is rotated and thereby causing the cutting element to oscillate.

32. The atherectomy catheter of claim 29, wherein the atherectomy catheter comprises a ramp having one or more raised portions, the cutting element comprises one or more raised portions on a cam surface of the cutting element, and the raised portions causing the cutting element to oscillate as the cutting element is rotated.

33. The atherectomy catheter of claim 29, wherein the cutting element has a cup-shaped surface, the cup-shaped surface being configured to re-direct tissue cut by the cutting edge in a distal direction when the cup-shaped surface moves in the distal direction.

34. The atherectomy catheter of claim 29, wherein the cutting edge is a radially outer edge of the cutting element.

35. The atherectomy catheter of claim 29, wherein the catheter comprises a raised element extending outwardly from the cup-shaped surface of the cutting element.

36. The atherectomy catheter of claim 35, wherein the cutting edge is a radially outer edge of the cutting element, and the raised element is recessed proximally from the cutting edge when viewed along the axis of rotation of the cutting element.

37. The atherectomy catheter of claim 29, wherein the cutting element is movable between a stored position and a cutting position relative to the opening.

38. The atherectomy catheter of claim 37, wherein the cutting element is moved between the stored position and the cutting position by sliding the cutting element against a cam surface.

39. The atherectomy catheter of claim 38, wherein a distal portion of the catheter relative to a proximal portion is deflected by sliding the cutting element against the cam surface.

40. A method of removing material from a body lumen, the method comprising:

providing an atherectomy catheter, the atherectomy catheter comprising;

a body having an opening;

a rotatable shaft coupled to the body;

a tissue collection chamber coupled to the body and positioned distal to the cutting element;

a cutting element coupled to the rotatable shaft for rotating the cutting element about an axis of rotation, the cutting element having a cup-shaped surface and a cutting edge, the cup-shaped surface being configured to re-direct tissue cut by the cutting edge in a distal direction when the cup-shaped surface moves in the distal direction; and

a raised element extending outwardly from the cup-shaped surface of the cutting element, the raised element being configured to direct cut particles of material towards one of more of the axis of rotation of the cutting element, a catheter longitudinal axis, or the tissue collection chamber;

placing the catheter in the body lumen; and

moving the catheter in the body lumen to contact the cutting element with the material in the body lumen.

41. The method of claim 40, wherein the catheter is moved in a distal direction to contact the cutting edge with the material in the body lumen.

42. The method of claim 40, wherein the catheter is placed in the body lumen with the cutting element in the stored position and the catheter is moved to contact the material with the cutting element in a cutting position.

43. The method of claim 40, wherein the body lumen is a blood vessel.

44. A method of removing material from a body lumen, the method comprising:

providing an atherectomy catheter, the atherectomy catheter comprising;

a body having an opening;

a rotatable shaft coupled to the body;

a tissue collection chamber coupled to the body and positioned distal to the cutting element; and

a cutting element coupled to the rotatable shaft for rotating the cutting element about an axis of rotation, the cutting element having a cutting edge, and the cutting element being configured to oscillate in a direction substantially parallel to the axis of rotation of the cutting element;

placing the catheter in the body lumen; and

moving the catheter in the body lumen to contact the cutting element with the material in the body lumen.

45. The method of claim 44, wherein the catheter is moved in a distal direction to contact the cutting edge with the material in the body lumen.

46. The method of claim 44, wherein the catheter is placed in the body lumen with the cutting element in the stored position and the catheter is moved to contact the material with the cutting element in a cutting position.

47. The method of claim 44, wherein the body lumen is a blood vessel.