Guidewire for crossing occlusions or stenoses having a shapeable distal end
A hollow guidewire with a shapeable distal end, for removing tissue from a body lumen, such as a coronary artery. The hollow guidewire comprises an elongate, tubular guidewire body that has an axial lumen. A tissue removal assembly, such as a rotating drive shaft, is positioned at or near a distal end of the tubular guidewire body and extends through the axial lumen. Actuation of the tissue removal assembly removes occlusive material in the body lumen.
1. A shapeable guidewire for crossing an occlusion or stenosis within a body lumen, said guidewire comprising:
a guidewire body having a proximal end, a distal end, and a central passage therethrough, wherein a distal region of the body is malleable so that said distal region may be manually configured to a desired curved shape; and
a mechanically driven core element disposed in the central passage and passing out through the distal end of the guidewire body, wherein the core element may be rotated, within the central passage while the distal region of the body retains its desired curved shape;
wherein the core element includes a cutting element that creates a cutting path when rotated.
2. A guidewire as in claim 1 , wherein the malleable distal region comprises a tube formed from a malleable metal.
3. A guidewire as in claim 2 , wherein the tube has a length and is slotted at least along a portion of said length.
4. A guidewire as in claim 3 , wherein one or more slots are formed along a helical spine of the tube.
5. A guidewire as in claim 4 , wherein the one or more slots along the helical spine have interruptions.
6. A guidewire as in claim 3 , wherein one or more slots are formed along an axial spine of the tube.
7. A guidewire as in claim 2 , wherein the tube has a length and is cut into a helical ribbon along at least a portion of said length.
8. A guidewire as in claim 1 , further comprising a spring element disposed along at least a portion of the malleable distal region wherein the spring element is aligned to help hold the desired curved shape.
9. A guidewire as in claim 8 , wherein, the spring element disposed along at the least portion of the malleable distal region comprises a strained linear spring element axially aligned along one side of the at least a portion of the malleable distal region, wherein the spring element has an arcuate memory and is configured to help hold an arc manually formed in the at least a portion of the malleable distal region when not under strain.
10. A guidewire a in claim 8 , wherein the spring element is formed from a shape memory material.
11. A guidewire as in claim 8 , wherein the malleable distal region and the core element are at least partially separated by a liner.
12. A guidewire as in claim 11 , wherein the liner is at least in part a coil.
13. A guidewire according to claim 1 , wherein the malleable distal region comprises a heat-sensitive component that is configured to be softened by heating.
14. A guidewire as in claim 13 , wherein the heat-sensitive component comprises a polymer jacket disposed along at least a portion of the malleable distal region.
15. A guidewire according to claim 1 , wherein the guidewire body is formed from either or both a first and a second solid walled tube.
16. A guidewire according to claim 15 , wherein the first solid walled tube extends proximally from at least a longitudinal portion of the malleable region to the proximal end of the guidewire.
17. A guidewire according to claim 15 , wherein the first solid walled tube extends proximally from at least a longitudinal portion of the malleable region, and a distal end of the second solid walled tube which extends to the proximal end of the guidewire body.
18. A guidewire according to claim 15 , wherein the first solid walled tube and the second solid walled tube are formed, respectively, from nickel titanium and stainless steel.
19. A guidewire according to claim 1 , wherein a housing is disposed at the proximal end of the guidewire body and contains a motor for moving the core element.
20. A guidewire according to claim 19 , wherein the motor is attached to a controller system.
21. A guidewire as in claim 20 , wherein the controller causes the motor to rotate the core element.
22. A guidewire according to claim 21 , wherein the controller oscillates the core element at a preset rotational speed and changes rotational direction at a preset period.
23. A guidewire as in claim 1 , wherein the core element comprises a drive shaft formed from nickel titanium.
24. A guidewire according to claim 1 , wherein the proximal end of the guidewire body is configured for attachment to a distal end of an extension body.
25. A method for crossing a luminal occlusion, said method comprising:
providing a shapeable guidewire;
manually shaping a distal end of the guidewire to impart a desired curved shape;
advancing the guidewire through an occlusion while a core carried by the guidewire is mechanically rotated to engage and penetrate the occlusion while the distal end of the guidewire;
wherein the core includes a cutting element that creates a cutting path when rotated.
26. A method as in claim 25 , wherein the core is rotated as the guidewire is advanced.
27. A method as in claim 25 , wherein manually shaping comprises shaping a spring element at the distal end of the guidewire, wherein the spring element helps to hold the curved shape of the distal end of the guidewire as the core is rotated.
28. A method as in claim 27 , wherein the distal end of the guidewire comprises a slotted tube.
29. A method as in claim 25 , further comprising advancing the guidewire while the core is not being rotated.