Mechanical thrombectomy apparatuses and methods
Methods and apparatuses for mechanically removing objects from a body. In particular, described herein are thrombectomy methods and mechanical thrombectomy apparatuses for removal of blood clots from within a lumen of a blood vessel.
1. A mechanical thrombectomy apparatus for removing a clot from a vessel, the apparatus comprising:
a catheter having a distal end, a distal end opening, and an inner diameter;
a knit tube extending through the catheter and doubling back over the distal end of the catheter, wherein the knit tube is configured to invert over the distal end opening when a first end of the knit tube is pulled proximally within the catheter,
wherein the knit tube is biased to have an outer diameter when inverted within the catheter that is greater than half the inner diameter of the catheter when the knit tube is pulled proximally from within the catheter so that an outer portion of the knit tube slides over an outside of the catheter to invert over the distal end opening,
further wherein the knit tube forms a distal-facing lip where the knit tube inverts over the distal end opening, the distal-facing lip having a larger outer diameter than an outer diameter of the outer portion of the knit tube proximal to the distal-facing lip; and
a puller extending within the catheter, the puller having a guidewire lumen configured to pass a guidewire, wherein the first end of the knitted tube is attached to the puller.
2. The apparatus of claim 1 , wherein the distal end of the catheter is configured to be compressed proximally so that it flares out.
3. The apparatus of claim 1 , wherein the knit tube is configured to radially compress 20% or less when the knit tube is pulled around the outside of the catheter distal end and into the catheter.
4. The apparatus of claim 1 , wherein the knit tube is configured to radially compress between 5-20% when the knit tube is pulled around the outside of the catheter distal end and into the catheter.
5. The apparatus of claim 1 , wherein the distal-facing lip has a tangential angle of between 10-60 degrees with respect to the long axis of the catheter outer diameter.
6. The apparatus of claim 1 , wherein the distal-facing lip has a tangential angle of at least 10 degrees with respect to the long axis of the catheter outer diameter.
7. The apparatus of claim 1 , wherein the knit tube is coupled to a distal end region of the puller.
8. The apparatus of claim 1 , wherein the knit tube has a porosity that is greater than 85%.
9. The apparatus of claim 1 , wherein the knit tube has a pore pattern having a longitudinal separation between pores of less than about 0.005 inches in width.
10. The apparatus of claim 1 , wherein the puller comprises a hypotube that is slidably disposed within the catheter.
11. The apparatus of claim 1 , wherein the knit tube is biased so that the outer diameter of the knit tube when inverted and unconstrained is greater than the inner diameter of the catheter.
12. The apparatus of claim 1 , wherein the knit tube is between 3 to 50 cm long.
13. A mechanical thrombectomy apparatus for removing a clot from a vessel, the apparatus comprising:
a catheter having a distal end, a distal end opening, an outer diameter and an inner diameter, wherein the distal end of the catheter is configured to be compressed proximally so that it flares out at the distal end;
a knit tube extending through the catheter and doubling back over the distal end of the catheter, wherein the knit tube is configured to invert over the distal end opening when a first end of the knit tube is pulled proximally within the catheter,
wherein the knit tube is biased to have an outer diameter when inverted within the catheter so that is the knitted tube radially compresses 20% or less when the knit tube is pulled around the outside of the catheter distal end and into the catheter so that an outer portion of the knit tube slides over an outside of the catheter to invert over the distal end opening,
further wherein the knit tube forms a distal-facing lip where the knit tube inverts over the distal end opening, the distal-facing lip having a larger outer diameter than an outer diameter of the outer portion of the knit tube proximal to the distal-facing lip; and
a puller extending within the catheter, the puller having a guidewire lumen configured to pass a guidewire, wherein the first end of the knitted tube is attached to the puller.
14. The apparatus of claim 13 , wherein the knit tube is configured to radially compress between 5-20% when the knit tube is pulled around the outside of the catheter distal end and into the catheter.
15. The apparatus of claim 13 , wherein the knit tube has a porosity that is greater than 85%.
16. The apparatus of claim 13 , wherein the knit tube has a pore pattern having a longitudinal separation between pores of less than about 0.005 inches in width.
17. The apparatus of claim 13 , wherein the puller comprises a hypotube that is slidably disposed within the catheter.
18. The apparatus of claim 13 , wherein the knit tube is biased so that the outer diameter of the knit tube when inverted and unconstrained is greater than the inner diameter of the catheter.
19. The apparatus of claim 13 , wherein the knit tube is between 3 to 50 cm long.
20. A mechanical thrombectomy apparatus for removing a clot from a vessel, the apparatus comprising:
a catheter having a distal end, a distal end opening, an outer diameter and an inner diameter, wherein the distal end of the catheter is configured to be compressed proximally so that it flares out at the distal end;
a knit tube extending through the catheter and doubling back over the distal end of the catheter, wherein the knit tube is configured to roll and invert over the distal end opening when a first end of the knit tube is pulled proximally within the catheter,
wherein the knit tube is biased to have an outer diameter when inverted within the catheter that is greater than half the inner diameter of the catheter when the knit tube is pulled proximally from within the catheter so that an outer portion of the knit tube slides over an outside of the catheter to invert over the distal end opening,
further wherein the knit tube forms a distal-facing lip where the knit tube inverts over the distal end opening, the distal-facing lip having a larger outer diameter than an outer diameter of the outer portion of the knit tube proximal to the distal-facing lip; and
a puller extending within the catheter, the puller having a guidewire lumen configured to pass a guidewire, wherein the first end of the knitted tube is attached to the puller.