Apparatus and methods for preventing or treating failure of hemodialysis vascular access and other vascular grafts
This invention is a prosthetic device generally placed on the outside surface of the vessel or graft which then elutes antiproliferative drugs or agents from a drug-eluting matrix material. Methods of perivascular antiproliferative drug administration also are disclosed.
1. An implantable biocompatible, biodegradable matrix comprising material of sufficient flexibility to wrap to be wrapped around the exterior of a human vascular structure that includes an anastomosis from the formation of an arterio-venous fistula or an arterio-venous graft or an arterial-arterial graft and carrying an anti-vasculoproliferative drug which is rapamycin or an analogue of rapamycin with similar antiproliferative activity, wherein the anti-vasculoproliferative drug is both carried in a sufficient amount between about 50 micrograms and 2 milligrams per cm 2 and elutes from the material, when the material is in place around the vascular structure, at a rate sufficient to delay or prevent the occlusion of the vascular structure.
2. The matrix material of claim 1 wherein its thickness is between about 0.3 and 2.0 mm.
3. The matrix material of claim 2 wherein it has a pore size between about 0.001 and 100 microns.
4. The matrix material of claim 1 wherein the biocompatible matrix material is a polymer.
5. The matrix material of claim 4 wherein the biocompatible matrix material is a resorbable protein matrix.
6. The matrix material of claim 5 wherein the biocompatible matrix material comprises collagen.
7. The matrix material of claim 6 wherein it has a pore size between about 0.001 and 100 microns.
8. The matrix material of claim 7 wherein it has a pore size between about 0.002 and 0.1 microns.
9. The matrix material of claim 5 wherein the biocompatible matrix material comprises fibrin.
10. The matrix material of claim 4 wherein the biocompatible matrix material comprises chitosan.