Covering for an endoprosthetic device and methods of using for aneurysm treatment

Abstract

The present invention relates to covered endoprosthetic devices. Covered endoprosthetic devices comprise an endoprosthesis and a sheath. The sheath comprises a central portion and outer portions, wherein the central portion preferentially restricts or causes a restriction of blood flow. Blood flow can be reduced by the central portion of the sheath by varying the permeability of the sheath or by having projections on the sheath that slow blood flow. Permeability may be provided by perforations or holes in the material of the sheath or by varying the polymer structure that makes up the sheath itself. The outer portions of the sheath do not substantially reduce blood flow. Methods of using sheath-covered endoprosthetic devices of the invention to treat aneurysms, especially aneurysms in proximity to small perforator vessels or arteries, are also encompassed.

1 - 40 . (canceled) 
     
     
         41 . A device for treating an aneurysm comprising:
 an endoprosthetic device; and   a sheath;   wherein the sheath comprises a central portion having a plurality of elongated flexible projections connected directly thereto and outer portions that do not have projections, each projection having a first end attached to the sheath and a second end unattached, said projections having a length longer than the diameter of any perforator vessel in proximity to said aneurysm that permits extension of said projections into said aneurysm but not substantially into adjacent perforator vessels, such that blood flow to the aneurysm is reduced while blood flow to a perforator vessel covered by the device is substantially maintained.   
     
     
         42 . The device of  claim 41 , wherein the endoprosthetic device is a stent. 
     
     
         43 . The device of  claim 41 , wherein the projections are between about 0.5 and 5.0 mm in length. 
     
     
         44 - 48 . (canceled) 
     
     
         49 . The device of  claim 41 , wherein the sheath is a porous polymer. 
     
     
         50 . The device of  claim 41 , wherein the projections are formed of a thin flexible material. 
     
     
         51 . The device of  claim 41 , wherein the projections are hair-like. 
     
     
         52 . The device of  claim 41 , wherein the sheath extends over only a central portion of the endoprosthetic device. 
     
     
         53 . The device of  claim 41 , wherein the projections are oriented to extend along only a first side of the sheath. 
     
     
         54 . The device of  claim 53 , wherein the projections extend along the sheath in a predetermined linear pattern. 
     
     
         55 . The device of  claim 41 , wherein the projections are configured such that a first portion thereof extends into the aneurysm and a second portion thereof remains external thereto, the second portion of the projections configured to fold in response to pressure applied thereto by walls of the perforator vessel. 
     
     
         56 . The device of  claim 41 , wherein the sheath is uniformly permeable. 
     
     
         57 . The device of  claim 56 , wherein the sheath is formed of a polymer with a porosity in the range of 10-100 micrometers over its length. 
     
     
         58 . The device of  claim 41 , wherein the projections are configured to cause thrombosis of the aneurysm. 
     
     
         59 . The device of  claim 41 , wherein at least one of the outer portions of the sheath is configured to face the one or more perforator vessels or arteries. 
     
     
         60 . The device of  claim 41 , wherein said sheath is coupled to said endoprosthetic device via an adhesive. 
     
     
         61 . The device of  claim 60 , wherein said sheath is configured to detach from said endoprosthetic device after a predetermined length of time has elapsed. 
     
     
         62 . The device of  claim 60 , wherein said sheath is configured to detach from said endoprosthetic device upon application of a force exceeding a predetermined magnitude thereto. 
     
     
         63 . A device for treating an aneurysm comprising:
 an endoprosthetic device; and   a sheath;   wherein said sheath comprises a plurality of hair-like projections, each projection having a first end attached to the sheath and a second end unattached, said projections having a length longer than the diameter of any perforator vessel in proximity to said aneurysm that permits extension of said projections into said aneurysm but not substantially into adjacent perforator vessels.   
     
     
         64 . A device for treating an aneurysm comprising:
 an endoprosthetic device; and   a sheath;   wherein said sheath comprises a plurality of thin flexible projections, each projection having a first end attached to the sheath and a second end unattached, and wherein said projections are between about 0.5 and 5.0 mm in length such that blood flow to the aneurysm is reduced while blood flow to a perforator vessel covered by the device is substantially maintained, said projections being configured such that a first portion thereof extends into the aneurysm and a second portion thereof remains external thereto, the second portion of the projections configured to fold in response to pressure applied thereto by walls of the perforator vessel.