Constrainable stent graft, delivery system and methods of use

Abstract

A stent graft for treating an arterial aneurysm includes a ligature traversing at least a portion of struts of stents, the ligature having ends that, when linked, at least partially constrict a radial dimension of the stents. The ends of the ligature can be linked by a wire in a stent graft delivery system that threads anchor loops longitudinally spanning ends of the ligature to maintain the stent in a radially constricted position during delivery to the aneurysm. The stent graft can be implanted at the aneurysm by retracting the wire from the linked ends of the ligature and from the anchor loops, thereby releasing the associated stent from the radially constricted position.

What is claimed is: 
     
         1 . A method of implanting a stent graft at an aneurysm site of a subject, comprising the steps of:
 a) advancing a stent graft through an artery to an arterial aneurysm of a subject, the stent graft including at least one ligature extending at least partially about a periphery of the stent graft and traversing struts of a radial stent of the stent graft, the stent graft including a plurality of radial stents, the ligature having ends that are linked by a wire extending parallel to a longitudinal axis of the stent graft and through anchor loops that are distributed longitudinally along a luminal graft component of the stent graft and thereby longitudinally span the linked ends of each associated ligature when the ends of each associated ligature are linked by a wire, thereby causing each associated ligature to radially constrict each corresponding stent and thereby maintain the stent graft in a radially constricted position, the pair of anchor loops thereby stabilizing the wire and preventing lateral migration of the wire during implantation of the stent graft; and   b) retracting the wire from the ends at least one ligature and the anchor loops, consequently releasing the ends of the ligature from each other, the stent graft radially expanding from the radially constricted position to a radially expanded position, thereby implanting the stent graft prosthesis at the arterial aneurysm of the subject.   
     
     
         2 . The method of  claim 1 , wherein
 a) the luminal graft component includes a proximal open end and a distal open end, and   b) the plurality of stents are distributed longitudinally along the luminal graft component.   
     
     
         3 . The method of  claim 1 , wherein each of the ligatures extends completely about a circumference of the stent when the ends are linked by the wire. 
     
     
         4 . The method of  claim 1 , wherein the ends of the ligature each include a ligature loop. 
     
     
         5 . The method of  claim 1 , wherein at least a portion of the ligatures are each circular and can be linked at diametrically opposed points by a wire threading the anchor loops when the ligature is radially constricting the luminal graft component. 
     
     
         6 . The method of  claim 1 , further including ligature sutures arranged laterally at the luminal graft component through which the ligature ends pass, the ligature sutures being located on either lateral side of the wire passing through the anchor loops, and wherein the ligature ends are linked by the wire between the ligature sutures. 
     
     
         7 . The method of  claim 1 , wherein the ligature includes two ligature component parts that extend partially about the circumference when the ends are linked, and wherein the ligature ends are linked. 
     
     
         8 . The method of  claim 7 , wherein the ligature ends each include a ligature loop. 
     
     
         9 . The method of  claim 8 , wherein the two component parts of the ligature are each fixed to the luminal graft component. 
     
     
         10 . The method of  claim 8 , wherein the two component parts of the ligature are fixed to a strut at an end opposite to the ligature loop of each component part of the ligature. 
     
     
         11 . The method of  claim 10 , further including ligature sutures arranged laterally at the luminal graft component through which the ligature ends pass, the ligature sutures being located on either side of the wire and passing through the anchor loops, and wherein the ligature ends can be linked by the wire between the ligature sutures. 
     
     
         12 . The method of  claim 7 , wherein the two component parts are each a circular thread that is secured to the luminal graft component or a strut of the associated stent at a point diametrically opposite the point of the circular thread that is linked to the circular thread of the other component part of the ligature. 
     
     
         13 . The method of  claim 1 , wherein the ligature is a thread. 
     
     
         14 . The method of  claim 13 , wherein the thread includes at least one member of the group consisting of polyester, nylon, expanded polytetrafluoroethylene (ePTFE), polyvinylidene fluoride (PVDF), and polypropylene. 
     
     
         15 . The method of  claim 1 , wherein the stent includes a shape-memory alloy. 
     
     
         16 . The method of  claim 15 , wherein the shape-memory alloy includes nitinol. 
     
     
         17 . The method of  claim 16 , wherein the stent further includes a radiopaque material.