Enhanced flexibility neurovascular catheter with tensile support
An enhanced flexibility neurovascular catheter is provided, such as for distal neurovascular access or aspiration. The catheter includes an elongate flexible body, having a proximal end, a distal end and a side wall defining a central lumen. A distal zone of the side wall includes an outer jacket surrounding a helical coil, and the outer jacket is formed from a plurality of tubular segments positioned coaxially about the coil. A proximal one of the tubular segments has a durometer of at least about 60D, and a distal one of the tubular segments has a durometer of no more than about 35D. An axially extending filament within the side wall extends at least about the most distal 10 cm of the length of the catheter. The axially extending filament serves as a tension support and resists elongation of the catheter wall under tension, such as when the catheter is being proximally retracted through tortuous vasculature.
1. An enhanced flexibility neurovascular catheter, comprising:
an elongate flexible body, having a proximal end, a distal end and a side wall defining a central lumen, a distal zone of the side wall comprising a helical coil,
wherein the elongated flexible body comprises an outer jacket formed from a plurality of tubular segments and extending coaxially about the coil, wherein a proximal one of the tubular segments has a durometer of at least about 60D and a distal one of the tubular segments has a durometer of no more than about 35D; and
wherein the elongated flexible body comprises an axially extending filament within the side wall, extending at least about the most distal 10 cm of the length of the catheter and less than about 40 cm from the distal end of the catheter, the filament configured to resist elongation of the catheter wall under tension,
wherein the axially extending filament extends proximally past a proximal end of the helical coil.
2. An enhanced flexibility neurovascular catheter as in claim 1 , wherein the filament extends at least about the most distal 15 cm of the length of the catheter.
3. An enhanced flexibility neurovascular catheter as in claim 2 , wherein the filament comprises multiple fibers.
4. An enhanced flexibility neurovascular catheter as in claim 2 , further comprising an inner liner, wherein the filament extends axially in between the coil and the inner liner.
5. An enhanced flexibility neurovascular catheter as in claim 2 , wherein the side wall further comprises:
a tubular inner liner;
a tie layer separated from the lumen by the inner liner;
wherein the helical coil surrounds the tie layer, and adjacent windings of the coil are spaced progressively further apart in the distal direction.
6. An enhanced flexibility neurovascular catheter as in claim 5 , wherein the tubular inner liner is formed by dip coating a removable mandrel.
7. An enhanced flexibility neurovascular catheter as in claim 5 , wherein the tubular inner liner comprises polytetrafluoroethylene.
8. An enhanced flexibility neurovascular catheter as in claim 5 , wherein the tie layer comprises polyurethane.
9. An enhanced flexibility neurovascular catheter as in claim 8 , wherein the tie layer has a wall thickness of no more than about 0.005 inches.
10. An enhanced flexibility neurovascular catheter as in claim 8 , wherein the tie layer extends along at least the most distal 20 cm of the flexible body.
11. An enhanced flexibility neurovascular catheter as in claim 5 , wherein the coil comprises a shape memory material.
12. An enhanced flexibility neurovascular catheter as in claim 11 , wherein the coil comprises Nitinol.
13. An enhanced flexibility neurovascular catheter as in claim 12 , wherein the Nitinol comprises an Austenite state at body temperature.
14. An enhanced flexibility neurovascular catheter as in claim 5 , wherein the outer jacket is formed from at least five discrete tubular segments.
15. An enhanced flexibility neurovascular catheter as in claim 5 , wherein the outer jacket is formed from at least nine discrete tubular segments.
16. An enhanced flexibility neurovascular catheter as in claim 15 , wherein the difference in durometer between a proximal one of the tubular segments and a distal one of the tubular segments is at least about 20D.
17. An enhanced flexibility neurovascular catheter as in claim 15 , wherein the difference in durometer between a proximal one of the tubular segments and a distal one of the tubular segments is at least about 30D.
18. An enhanced flexibility neurovascular catheter as in claim 1 , wherein the filament extends at least about the most distal 20 cm of the length of the catheter.
19. An enhanced flexibility neurovascular catheter as in claim 1 , wherein the catheter can withstand at least about 3.5 pounds tension before failure.
20. An enhanced flexibility neurovascular catheter as in claim 1 , wherein the catheter can withstand at least about 5 pounds tension before failure.
21. An enhanced flexibility neurovascular catheter as in claim 1 , wherein the catheter can withstand at least about 7 pounds tension before failure.