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 plurality of struts,
a proximal face, and
a distal face,
wherein the generally cylindrical section at least partially defines a device lumen extending in an axial direction from the proximal face towards the distal face, and
wherein the device lumen is configured to allow blood flow through the device; and
a proximal tapered section comprising a plurality of struts extending from a perimeter of the proximal face to a proximal apex, the proximal apex being radially aligned with the perimeter of the proximal face or being positioned radially outside of the perimeter of the proximal face, each of the plurality of struts of the proximal tapered section extending from a different point on the perimeter of the proximal face in a direction along the perimeter and towards the proximal apex such that none of the plurality of struts cross through a cross-sectional area defined by a proximal face of the device lumen;
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 perimeter of the proximal face such that the proximal apex is positioned radially outside the perimeter of the proximal face.
2. 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, and wherein the braided wires are at least partially braided within the proximal tapered section.
3. The device of claim 1 , 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 end of each of the plurality of struts are substantially uniformly distributed around a circumference of the push wire.
4. The device of claim 3 , wherein the push wire is permanently joined to the proximal tapered section.
5. The device of claim 3 , wherein the push wire is detachably joined to the proximal tapered section.
6. 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 extend to the perimeter of the proximal face, wherein the edge is configured to interface incoming blood flow, wherein the edge defines a take-off angle relative to a longitudinal axis extending through the proximal apex parallel to an axial dimension, and wherein the take-off angle being no greater than about 80 degrees.
7. The device of claim 1 , wherein the plurality of struts of the proximal tapered section have a diameter of no greater than about 0.01 inches, and wherein the plurality of struts the generally cylindrical section have a diameter of no greater than about 0.01 inches.
8. The device of claim 1 , wherein the generally cylindrical section further comprises a middle section configured to be positioned adjacent the aneurysm, and wherein the middle section comprises a substantially higher strut density than at least a portion of a remainder of the generally cylindrical section.
9. The device of claim 8 , wherein the middle section comprises an outer diameter that is larger than an outer diameter of the proximal face in an unconstrained configuration.
10. The device of claim 1 , wherein each of the interstitial gaps in the generally cylindrical section are no greater than about 0.01 inches across.
11. The device of claim 1 , further comprising a distal tapered section comprising a plurality of struts each extending from a perimeter of the distal face to a distal apex, the distal apex being radially aligned with the perimeter of the distal face or being positioned radially outside the perimeter of the distal face, each of the plurality of struts of the distal tapered section extending from a different point on the perimeter of the distal face in a direction along the perimeter of the distal face and towards the distal apex such that none of the plurality of struts cross through a cross-sectional area defined by a distal face of the device lumen.
12. The device of claim 1 , wherein the distal face is open and substantially perpendicular to the axial direction.
13. The device of claim 1 , wherein the plurality of struts within the proximal tapered section are distributed substantially uniformly around the perimeter of the proximal face.
14. The device of claim 1 , further comprising a polymeric sleeve positioned around at least a portion of the device lumen.
15. The device of claim 14 , wherein the polymeric sleeve comprises one or more apertures positioned near a proximal end of the polymeric sleeve and near a distal end of the polymeric sleeve but not within a middle section of the polymeric sleeve.
16. The device of claim 14 , wherein the polymeric sleeve comprises an A:B:A triblock copolymer, wherein the A block comprises tetrafluoroethylene (TFE), ethylene, and hexafluoropropylene (HFP) and wherein the B block comprises vinlidene fluoride (VDF), hexafluoropropylene (HFP), and tetrafluoroethylene (TFE).
17. The device of claim 14 , wherein the polymeric 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.
18. The device of claim 1 , further comprising:
an internal surface defining an internal diameter, the internal surface comprising a first coating, and
an outer surface defining an outer diameter, the outer surface comprising a second coating, the second coating having biological properties distinct from the first coating.
19. The device of claim 18 , wherein the first coating is designed primarily to reduce thrombus formation and the second coating is designed primarily to promote endothelialization.
20. The device of claim 1 , wherein the generally cylindrical section further comprises a middle section, and wherein a radial force at the proximal tapered section is greater than a radial force at the middle section.