Surgical graft/stent system

Abstract

A tubular graft/stent includes a tubular sheath ( 10 ) having at intervals along its length a plurality of ring-like rigid members ( 11 ), which are attached to the sheath around their respective circumferences and are made of a shape memory material, so that when the members ( 11 ) change shape the sheath ( 10 ) adopts a new cross section in conformity with them along its whole length. The members may be discontinuous to allow the adoption of a contracted shape in the martensitic phase and an expanded shape in the austenitic phase. A graft may also have a side tube ( 14 ) which can be inverted so as to be housed within the sheath.

1. A tubular graft/stent comprising:
 a tubular sheath that is graft/stent; and  
 an integral branch tube having an end fixed to the tubular sheath at an opening in a side wall of the tubular sheath, wherein the branch tube is a graft/stent along its entire length, the branch tube comprising a plurality of rigid ring-like members being of progressively smaller size in the direction progressively away from the tubular sheath, and the branch tube being sufficiently flexible to be fully inverted along its entire length so as to be fully housed within the tubular sheath during an insertion operation in a human or animal body, and to be redeployed as a branch after insertion operation.  
 
     
     
       2. A tubular graft/stent according to  claim 1 , wherein the rigid ring-like members are made of a shape memory material, so that when said members change shape the sheath adopts a new cross-section in conformity with them along its whole length. 
     
     
       3. A tubular graft/stent according to  claim 1 , wherein the rigid members are attached to the sheath around their respective peripheries. 
     
     
       4. A tubular graft/stent according to  claim 1 , wherein said members are discontinuous to allow them to adopt a contracted shape in the martensitic phase, and an expanded shape of larger circumference in the austenitic phase. 
     
     
       5. A tubular graft/stent according to  claim 1 , wherein said members can be caused to adopt a spiral form as the contracted shape and a generally circular form as the expanded shape. 
     
     
       6. A tubular graft/stent according to  claim 1 , wherein the rigid ring-like members are embedded in a compliant material that is cast around said members to form the sheath. 
     
     
       7. A tubular graft/stent according to  claim 1 , wherein the rigid ring-like members are held in pockets formed in the material of the sheath. 
     
     
       8. A tubular graft/stent according to  claim 1 , wherein the members are trapped between two layers of material which together form the sheath. 
     
     
       9. A tubular graft/stent according to  claim 1 , wherein the members include portions which project from the outer surface of the graft in its new cross-section, such projecting portions forming anchors for locating the graft in position in a body. 
     
     
       10. A tubular graft/stent according to  claim 1 , wherein the branch tube has a draw string attached at its free end such that when inverted into the sheath the draw string may be pulled to redeploy the branch tube outside the sheath. 
     
     
       11. A method of inserting a graft/stent having a tubular sheath which is a graft/stent and an attached integral branch tube that is also a graft/stent along its entire length, the method comprising:
 fully inverting said branch tube along its entire length to place said branch tube fully within said tubular sheath for insertion in a body;  
 inserting said graft/stent into said body; and  
 pulling said branch tube out of said tubular sheath in said body, wherein pulling said tubular branch tube re-inverts said branch tube and leaves said branch tube attached to said tubular sheath.  
 
     
     
       12. The method of  claim 11 , wherein pulling said branch tube comprises:
 engaging a cord on a distal end of said branch tube; and  
 pulling said cord to deploy said branch tube within said body.  
 
     
     
       13. The method of  claim 12 , wherein said cord is selected from the group consisting of a draw string, short handle, tab, and strip. 
     
     
       14. The method of  claim 11  wherein the sheath includes at least one ring-like member along its length which is made of a shape memory material, and wherein the method further comprises the step of cooling the member. 
     
     
       15. The method of  claim 11  wherein the sheath includes at least one ring-like member along its length, the member having a variable shape wherein it may be at least partially coiled, wherein the method further comprises the step of uncoiling the member. 
     
     
       16. The method of  claim 11  wherein the sheath is defined by material which is at least partially coiled, wherein the method further comprises the step of uncoiling the sheath from a small-diameter state to a large-diameter state.