Thromboresistant coatings for aneurysm treatment devices
Disclosed are coating compositions, processes, and designs for endowing vascular devices with thromboresistant and endothelializing properties. Also disclosed are designs of vascular devices used as aneurysm treating devices for assisting in the delivery, packing, and maintenance of embolization coils within an aneurysm, particularly a neurovascular aneurysm.
1. A device for insertion into a blood vessel lumen for treatment of an aneurysm, the device comprising:
a generally cylindrical section comprising a plurality of struts forming interstitial gaps between the struts, the generally cylindrical section comprising:
a proximal face,
a distal face, and
a middle section being configured to be positioned adjacent an aneurysm, the middle section comprising a substantially higher strut density than at least a portion of a remainder of the generally cylindrical section,
wherein the generally cylindrical section at least partially defining a device lumen extending along an axial direction from the proximal face to the distal face, and wherein the lumen is configured to allow blood flow through the device; and
a proximal tapered section comprising a plurality of struts extending from a circumference of the proximal face to a proximal apex,
wherein the proximal apex is radially aligned with the circumference of the proximal face or positioned radially outside the circumference of the proximal face,
wherein the plurality of struts of the proximal tapered section extend from different points on the circumference of the proximal face in an axial and circumferential direction to the proximal apex, such that none of the plurality of struts cross through a cross-sectional area defined by the device lumen,
wherein at least a portion of each of the plurality of struts within the proximal tapered section is aligned in a parallel fashion proximal to the proximal apex, wherein a proximal end of each of the plurality of struts is joined to a distal end of a push wire at a location collinear with the proximal apex, and wherein the proximal ends of each of the plurality of struts are substantially uniformly distributed around a circumference of the push wire.
2. The device of claim 1 , wherein the cylindrical section comprises a wire weave.
3. The device of claim 1 , wherein the plurality of struts of the generally cylindrical section and the proximal tapered section are formed from braided wires which are at least partially braided within the proximal tapered section.
4. The device of claim 3 , wherein the interstitial gaps are no greater than about 0.01 inches across.
5. The device of claim 3 , wherein the plurality of struts of the generally cylindrical section and the proximal tapered section are formed from 24 braided wires.
6. The device of claim 3 , wherein the push wire is permanently joined to the proximal tapered section.
7. The device of claim 3 , wherein the push wire is detachably joined to the proximal tapered section.
8. The device of claim 3 , wherein the distal end of the push wire comprises a tapered portion.
9. The device of claim 3 , wherein the distal end of the push wire comprises a plurality of plastic rings surrounding the push wire, the proximal ends of the plurality of struts from the proximal tapered section surrounding the plastic rings.
10. The device of claim 1 , wherein one or more of the plurality of struts of the proximal tapered section are inverted within the proximal tapered section such that one or more of the inverted struts bend radially outward of the circumference of the proximal face such that the proximal apex is positioned radially outside the circumference of the proximal face.
11. The device of claim 1 , wherein the plurality of struts of the proximal tapered section form an edge extending from or near the proximal apex and extending to the circumference of the proximal face configured to interface incoming blood flow, and wherein the edge defines a take-off angle relative to a longitudinal axis extending through the proximal apex parallel to the axial dimension, the take-off angle being no greater than about 80 degrees.
12. The device of claim 11 , wherein the take-off angle is at least about 30 degrees.
13. The device of claim 1 , wherein the plurality of struts of the proximal tapered section and the generally cylindrical section have a diameter of no greater than about 0.01 inches.
14. The device of claim 1 , wherein the middle section comprises an outer diameter that is larger than an outer diameter of the proximal face in an unconstrained configuration.
15. The device of claim 1 , further comprising a distal tapered section comprising a plurality of struts extending from a circumference of the distal face to a distal apex,
wherein the distal apex is radially aligned with the circumference of the distal face or positioned radially outside the circumference of the distal face, and
wherein the plurality of struts of the distal tapered section extend from different points on the circumference of the distal face in an axial and circumferential direction to the distal apex, such that none of the plurality of struts cross through a cross-sectional area defined by the device lumen.
16. The device of claim 1 , wherein the distal face is open and substantially perpendicular to the axial direction.
17. The device of claim 1 , wherein the plurality of struts within the proximal tapered section are distributed substantially uniformly around the circumference of the proximal face.
18. The device of claim 1 , further comprising a polymeric sleeve positioned around at least a portion of the device lumen.
19. The device of claim 18 , wherein the sleeve comprises apertures positioned near a proximal end of the sleeve and near a distal end of the sleeve but not within the middle section of the sleeve.
20. The device of claim 18 , wherein the sleeve comprises fluorinated ethylene propylene (FEP), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), or poly(vinylidene fluoride co-hexafluoropropylene) (PVDF-HFP).
21. The device of claim 18 , wherein the sleeve comprises an A:B:A triblock copolymer, the A block comprising tetrafluoroethylene (TFE), ethylene, and hexafluoropropylene (HFP) and the B block comprising vinlidene fluoride (VDF), hexafluoropropylene (HFP), and tetrafluoroethylene (TFE).
22. The device of claim 18 , wherein the sleeve is impregnated with or coated with polyvinylpyrrolidone (PVP), phosphorylcholine (PC), polyethylene glycol (PEG), Serene™, PEG-ylated molecules, or fluorinated molecules to provide a thromboresistant surface.
23. The device of claim 1 , wherein the device comprises an internal surface with an internal diameter and an outer surface with an outer diameter, wherein the device further comprises a first coating applied to the internal surface and a second coating applied to the outer surface, and wherein the first and second coatings having distinct biological properties.
24. The device of claim 23 , wherein the first coating is designed primarily to reduce thrombus formation and the second coating is designed primarily to promote endothelialization.
25. The device of claim 1 , wherein the plurality of struts of the generally cylindrical section are coated with polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyvinylidene-hexafluoropropylene (PVDF-HFP), perfluoropropylene, octafluoropropane, Parylene HT, Parylene AF-4, Parylene F, Parylene VT-4; 1H,1H,2H,2H-perfluorododecyltrichlorosilane, (tridecafluoro-1,1,2,2, tetrahydrooctyle) silane, hexadecafluordodec-11-en-1-yl trimethoxysilane, or a poly(p-xylylene) polymer.
26. The device of claim 1 , wherein the proximal apex is positioned radially outside the circumference of the proximal face.