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 . 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 curved along the longitudinal axis for placement at an anastomosis site.   
     
     
         2 . The stent of  claim 1 , wherein the degree of curvature in the stent is approximately 5 degrees. 
     
     
         3 . The stent of  claim 1 , wherein the degree of curvature in the stent is approximately 10 degrees. 
     
     
         4 . The stent of  claim 1 , wherein the degree of curvature in the stent is approximately 15 degrees. 
     
     
         5 . The stent of  claim 1 , wherein the degree of curvature in the stent is approximately 20 degrees. 
     
     
         6 . The stent of  claim 1 , wherein the degree of curvature in the stent is approximately 25 degrees. 
     
     
         7 . The stent of  claim 1 , wherein the degree of curvature in the stent is approximately degrees. 
     
     
         8 . The stent of  claim 1 , wherein the degree of curvature in the stent is approximately degrees. 
     
     
         9 . The stent of  claim 1 , wherein the degree of curvature in the stent is approximately 40 degrees. 
     
     
         10 . The stent of  claim 1 , wherein the degree of curvature in the stent is approximately 45 degrees. 
     
     
         11 . The stent of  claim 1 , wherein the degree of curvature in the stent is approximately 50 degrees. 
     
     
         12 . The stent of  claim 1 , wherein the degree of curvature in the stent is approximately 55 degrees. 
     
     
         13 . The stent of  claim 1 , wherein the degree of curvature in the stent is approximately 60 degrees. 
     
     
         14 . The stent of  claim 1 , wherein the degree of curvature in the stent is approximately 65 degrees. 
     
     
         15 . The stent of  claim 1 , wherein the degree of curvature in the stent is approximately 70 degrees. 
     
     
         16 . The stent of  claim 1 , wherein the degree of curvature in the stent is approximately 75 degrees. 
     
     
         17 . The stent of  claim 1 , wherein the degree of curvature in the stent is approximately 80 degrees. 
     
     
         18 . The stent of  claim 1 , wherein the degree of curvature in the stent is approximately 85 degrees. 
     
     
         19 . The stent of  claim 1 , wherein the degree of curvature in the stent is approximately 90 degrees. 
     
     
         20 . The stent of  claim 1 , wherein the degree of curvature in the stent is approximately 95 degrees. 
     
     
         21 . The stent of  claim 1 , wherein the degree of curvature in the stent is approximately 100 degrees. 
     
     
         22 . The stent of  claim 1 , wherein the degree of curvature in the stent is approximately 105 degrees. 
     
     
         23 . The stent of  claim 1 , wherein the degree of curvature in the stent is approximately 110 degrees. 
     
     
         24 . The stent of  claim 1 , wherein the degree of curvature in the stent is approximately 115 degrees. 
     
     
         25 . The stent of  claim 1 , wherein the degree of curvature in the stent is approximately 120 degrees. 
     
     
         26 . The stent of  claim 1 , wherein the degree of curvature in the stent is approximately 125 degrees. 
     
     
         27 . The stent of  claim 1 , wherein the degree of curvature in the stent is approximately 130 degrees. 
     
     
         28 . The stent of  claim 1 , wherein the degree of curvature in the stent is approximately 135 degrees. 
     
     
         29 . The stent of  claim 1 , wherein the degree of curvature in the stent is approximately 140 degrees. 
     
     
         30 . The stent of  claim 1 , wherein the stent is a drug eluting stent. 
     
     
         31 . The stent of  claim 30 , wherein the drug is an anti-proliferative drug. 
     
     
         32 . The stent of  claim 30 , wherein the drug is rapamycin. 
     
     
         33 . The stent of  claim 30 , wherein the drug is an analogue of rapamycin. 
     
     
         34 . The stent of  claim 30 , wherein the drug is everolimus. 
     
     
         35 . The stent of  claim 30 , wherein the drug is dexamethasone. 
     
     
         36 . The stent of  claim 30 , wherein the drug is paclitaxel. 
     
     
         37 . The stent of  claim 30 , wherein the drug is tacrolimus. 
     
     
         38 . The stent of  claim 1 , further comprising a wire affixed to the outer surface of the stent in its compressed state, wherein manipulating the wire pulls the exterior surface of the stent toward the internal surface of the vessel, expanding the stent to abut the interior vascular or graft wall. 
     
     
         39 . The stent of  claim 38 , wherein the stent is a drug eluting stent. 
     
     
         40 . The stent of  claim 39 , wherein the drug is an anti-proliferative drug. 
     
     
         41 . The stent of  claim 39 , wherein the drug is rapamycin. 
     
     
         42 . The stent of  claim 39 , wherein the drug is an analogue of rapamycin. 
     
     
         43 . The stent of  claim 39 , wherein the drug is everolimus. 
     
     
         44 . The stent of  claim 39 , wherein the drug is dexamethasone. 
     
     
         45 . The stent of  claim 39 , wherein the drug is paclitaxel. 
     
     
         46 . The stent of  claim 39 , wherein the drug is tacrolimus. 
     
     
         47 . A method for preventing stenosis at an anastomosis site, 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 curved along the longitudinal axis for placement in an 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 an anastomosis site; and   d. Inserting the stent into the vein and graft orifice of an anastomosis site.   
     
     
         48 . The method of  claim 47 , wherein the therapeutic agent is rapamycin. 
     
     
         49 . The method of  claim 47 , wherein the therapeutic agent is an analogue of rapamycin. 
     
     
         50 . The method of  claim 47 , wherein the therapeutic agent is everolimus. 
     
     
         51 . The method of  claim 47 , wherein the therapeutic agent is dexamethasone. 
     
     
         52 . The method of  claim 47 , wherein the therapeutic agent is paclitaxel. 
     
     
         53 . The method of  claim 47 , wherein the therapeutic agent is tacrolimus. 
     
     
         54 . The method of  claim 47 , wherein the matrix material comprises collagen. 
     
     
         55 . The method of  claim 54 , wherein the collagen is Type I Bovine collagen. 
     
     
         56 . The method of  claim 54 , wherein the collagen is selected from the group consisting of Type I, Type II, Type III, Type IV, Type XI, and mixtures thereof. 
     
     
         57 . The method of  claim 47 , wherein the matrix material comprises fibrin. 
     
     
         58 . The method of  claim 47 , wherein the matrix material comprises a polysaccharide. 
     
     
         59 . The method of  claim 58 , wherein the polysaccharide is chitosan. 
     
     
         60 . The method of  claim 47 , wherein the matrix material is selected from the group consisting of collagen, fibrin, chitosan, and mixtures thereof. 
     
     
         61 . The method of  claim 47 , wherein the stent is a drug eluting stent. 
     
     
         62 . The method of  claim 61 , wherein the drug is an anti-proliferative drug. 
     
     
         63 . The method of  claim 61 , wherein the drug is rapamycin. 
     
     
         64 . The method of  claim 61 , wherein the drug is an analogue of rapamycin. 
     
     
         65 . The method of  claim 61 , wherein the drug is everolimus. 
     
     
         66 . The method of  claim 61 , wherein the drug is dexamethasone. 
     
     
         67 . The method of  claim 61 , wherein the drug is paclitaxel. 
     
     
         68 . The method of  claim 61 , wherein the drug is tacrolimus. 
     
     
         69 . The method of  claim 47 , 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 graft orifice of an anastomosis site;   b. Manipulating the external wire to pull the external surface of the stent toward the internal surface of the vessel, expanding the stent to abut the interior vascular or graft wall.   
     
     
         70 . The method of  claim 69 , wherein the stent is a drug eluting stent. 
     
     
         71 . The method of  claim 70 , wherein the drug is an anti-proliferative drug. 
     
     
         72 . The method of  claim 70 , wherein the drug is rapamycin. 
     
     
         73 . The method of  claim 70 , wherein the drug is an analogue of rapamycin. 
     
     
         74 . The method of  claim 70 , wherein the drug is everolimus. 
     
     
         75 . The method of  claim 70 , wherein the drug is dexamethasone. 
     
     
         76 . The method of  claim 70 , wherein the drug is paclitaxel. 
     
     
         77 . The method of  claim 70 , wherein the drug is tacrolimus. 
     
     
         78 . A method for preventing stenosis at an anastomosis site 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 curved along the longitudinal axis for placement in an 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 an anastomosis site;   d. Directing the stent delivery system to an anastomosis site;   e. Retracting the sheath, wherein retraction of said sheath causes the stent to expand and abut the internal vascular or graft wall.   
     
     
         79 . The method of  claim 78 , wherein the stent is a drug eluting stent. 
     
     
         80 . The method of  claim 79 , wherein the drug is an anti-proliferative drug. 
     
     
         81 . The method of  claim 79 , wherein the drug is rapamycin. 
     
     
         82 . The method of  claim 79 , wherein the drug is an analogue of rapamycin. 
     
     
         83 . The method of  claim 79 , wherein the drug is everolimus. 
     
     
         84 . The method of  claim 79 , wherein the drug is dexamethasone. 
     
     
         85 . The method of  claim 79 , wherein the drug is paclitaxel. 
     
     
         86 . The method of  claim 79 , wherein the drug is tacrolimus. 
     
     
         87 . A kit for preventing stenosis at an anastomosis site, comprising:
 a. a stent comprising 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 curved along the longitudinal axis for placement in an anastomosis site; and   b. a sleeve comprising a biocompatible matrix material imbibed with a therapeutic agent.   
     
     
         88 . The kit of  claim 87 , wherein the therapeutic agent is rapamycin. 
     
     
         89 . The kit of  claim 87 , wherein the therapeutic agent is an analogue of rapamycin. 
     
     
         90 . The kit of  claim 87 , wherein the therapeutic agent is everolimus. 
     
     
         91 . The kit of  claim 87 , wherein the therapeutic agent is dexamethasone. 
     
     
         92 . The kit of  claim 87 , wherein the therapeutic agent is paclitaxel. 
     
     
         93 . The kit of  claim 87 , wherein the therapeutic agent is tacrolimus. 
     
     
         94 . The kit of  claim 87 , wherein the matrix material comprises collagen. 
     
     
         95 . The kit of  claim 94 , wherein the collagen is Type I Bovine collagen. 
     
     
         96 . The kit of  claim 94 , wherein the collagen is selected from the group consisting of Type I, Type II, Type III, Type IV, Type XI, and mixtures thereof. 
     
     
         97 . The kit of  claim 87 , wherein the matrix material comprises fibrin. 
     
     
         98 . The kit of  claim 87 , wherein the matrix material comprises a polysaccharide. 
     
     
         99 . The kit of  claim 98 , wherein the polysaccharide is chitosan. 
     
     
         100 . The kit of  claim 87 , wherein the matrix material is selected from the group consisting of collagen, fibrin, chitosan, and mixtures thereof. 
     
     
         101 . The kit of  claim 78 , wherein the stent is a drug eluting stent. 
     
     
         102 . The kit of  claim 101 , wherein the drug is an anti-proliferative drug. 
     
     
         103 . The kit of  claim 101 , wherein the drug is rapamycin. 
     
     
         104 . The kit of  claim 101 , wherein the drug is an analogue of rapamycin. 
     
     
         105 . The kit of  claim 101 , wherein the drug is everolimus. 
     
     
         106 . The kit of  claim 101 , wherein the drug is dexamethasone. 
     
     
         107 . The kit of  claim 101 , wherein the drug is paclitaxel. 
     
     
         108 . The kit of  claim 101 , wherein the drug is tacrolimus. 
     
     
         109 . A method for preventing stenosis at an anastomosis of an AV fistula, 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 curved along the longitudinal axis for placement at the anastomosis; and   b. Inserting the stent into the vein and graft orifice of the anastomosis, wherein the placement of the stent at or around the anastomosis prevents the narrowing of the outflow vein.