Device and method for preventing stenosis at an anastomosis site

Abstract

The present invention relates to treating or preventing stenosis at an anastomosis site. In one embodiment, the present invention is a stent is curved along the longitudinal axis for placement in and adjacent to the graft orifice. In a further embodiment, the stent is drug coated to allow delivery of antivasculoproliferative drugs directly to the vicinity of the graft orifice. In a further embodiment, the stent is expandable by use of an external wire. In another embodiment, the present invention is a kit comprising the specially configured stent together with a sleeve comprising a biocompatible matrix material and a pharmaceutical agent, wherein the sleeve is applied to the external surface of the vessel or graft, resulting in extravascular delivery of a pharmaceutical agent. Methods for treating or preventing stenosis at an anastomosis site by applying the extravascular sleeve and the intravascular stent are also provided.

1 - 109 . (canceled) 
     
     
         110 . A method for preventing stenosis of a vein, a graft, an artery, a vessel, and an anastomotic orifice at an anastomosis site having an extravascular surface, comprising the steps of:
 a. Providing a stent comprising a structure defining an essentially tubular body having a tubular wall with a longitudinal axis and a circumferential diameter, the structure being expandable from a contracted configuration to an expanded configuration, wherein the stent is beveled at the edge and curved along the longitudinal axis for placement in the anastomosis site;   b. Providing a sleeve comprising a biocompatible matrix material imbibed with a therapeutic agent;   c. Applying the sleeve to the extravascular surface of the anastomosis site; and   d. Inserting the stent into the vein and the anastomotic orifice of the anastomosis site.   
     
     
         111 . The method of  claim 110 , wherein the therapeutic agent is rapamycin. 
     
     
         112 . The method of  claim 110 , wherein the therapeutic agent is an analogue of rapamycin. 
     
     
         113 . The method of  claim 110 , wherein the therapeutic agent is selected from the group consisting of everolimus, dexamethasone, paclitaxel, and tacrolimus. 
     
     
         114 . The method of  claim 110 , wherein the matrix material comprises collagen. 
     
     
         115 . The method of  claim 114 , wherein the collagen is Type I Bovine collagen. 
     
     
         116 . The method of  claim 114 , wherein the collagen is selected from the group consisting of Type I, Type II, Type III, Type IV, Type XI, and mixtures thereof. 
     
     
         117 . The method of  claim 110 , wherein the matrix material comprises fibrin. 
     
     
         118 . The method of  claim 110 , wherein the matrix material comprises a polysaccharide. 
     
     
         119 . The method of  claim 118 , wherein the polysaccharide is chitosan. 
     
     
         120 . The method of  claim 110 , wherein the matrix material is selected from the group consisting of collagen, fibrin, chitosan, and mixtures thereof. 
     
     
         121 . The method of  claim 110 , wherein the stent is a drug eluting stent. 
     
     
         122 . The method of  claim 110 , wherein the drug is an anti-proliferative drug selected from the group consisting of rapamycin, analogue of rapamycin, everolimus, dexamethasone, paclitaxel, and tacrolimus. 
     
     
         123 . The method of  claim 110 , wherein the provided stent further comprises a wire affixed to the external surface of the stent in its compressed state, and wherein inserting the stent further comprises the steps of:
 a. Inserting the stent in its contracted state into the vein and the anastomotic orifice of the anastomosis site;   b. Manipulating the external wire to pull the external surface of the stent toward an interior surface of the vessel, expanding the stent to abut the interior surface of the vessel or graft.   
     
     
         124 . The method of  claim 123 , wherein the stent is a drug eluting stent. 
     
     
         125 . The method of  claim 124 , wherein the drug is an anti-proliferative drug selected from the group consisting of rapamycin, an analogue of rapamycin, everolimus, dexamethasone, paclitaxel, and tacrolimus. 
     
     
         126 . A method for preventing stenosis of a vein, a graft, an artery, a vessel, and an anastomotic orifice at an anastomosis site having an extravascular surface comprising the steps of:
 a. Providing a stent delivery system comprising:
 i. a stent in its contracted configuration, wherein the stent is a web structure defining an essentially tubular body having a tubular wall with a longitudinal axis and a circumferential diameter, the web structure being expandable from a contracted configuration to an expanded configuration, wherein the stent is beveled at the edge and curved along the longitudinal axis for placement in the anastomosis site; and 
 ii. a sheath surrounding said stent to constrict the stent to its contracted state; 
   b. Providing a sleeve comprising a biocompatible matrix material imbibed with a therapeutic agent;   c. Applying the sleeve to the extravascular surface of the anastomosis site;   d. Directing the stent delivery system to the anastomosis site;   e. Retracting the sheath, wherein retraction of said sheath causes the stent to expand and abut an interior surface of the wall of the vessel or graft.   
     
     
         127 . The method of  claim 126 , wherein the stent is a drug eluting stent. 
     
     
         128 . The method of  claim 125 , wherein the drug is an anti-proliferative drug selected from the group consisting of rapamycin, an analogue of rapamycin, everolimus, dexamethasone, paclitaxel, and tacrolimus. 
     
     
         129 . A method for preventing stenosis of an AV fistula at an anastomosis having an anastomotic orifice, wherein the AV fistula consists of a vein joined or attached to an artery, comprising the steps of:
 a. Providing a stent comprising a structure defining an essentially tubular body having a tubular wall with a longitudinal axis and a circumferential diameter, the structure being expandable from a contracted configuration to an expanded configuration, wherein the stent is beveled at the edge and curved along the longitudinal axis for placement at the anastomosis; and   b. Inserting the stent into the vein and the anastomotic orifice of the anastomosis, wherein the placement of the stent at or around the anastomosis prevents the narrowing of the vein.