Branch stent graft for aortic aneurysm repair

Abstract

Described is a removable shunt adapted for deployment along a brain-supplying artery into an aorta to supply blood to the artery during deployment of a stent-graft in the aorta, the removable shunt including a stiff segment that is stiff enough to remain at least partially open when between the aorta and the stent-graft and large enough to allow sufficient blood supply to the brain during the deployment of the stent-graft; and a mechanism for facilitating safe removal of the shunt from between the stent-graft and the aorta. Also described is a method of deploying a branch stent graft having a flaring portion in a blood vessel branching at a bifurcation from an aorta to connect to an aortic stent graft deployed in the aorta across the bifurcation, a branch stent-graft useful in the method, and a delivery system useful in the method.

1 . A removable shunt adapted for deployment along a brain-supplying artery into an aorta to supply blood to the artery during deployment of a stent-graft in the aorta, the removable shunt comprising
 a stiff segment that is stiff enough to remain at least partially open when between the aorta and the stent-graft and large enough to allow sufficient blood supply to the brain during the deployment of the stent-graft, and   a mechanism for facilitating safe removal of the shunt from between the stent-graft and the aorta.   
     
     
         2 . A removable shunt according to  claim 1 , wherein said mechanism includes an invertible sleeve. 
     
     
         3 . A removable shunt according to  claim 2 , wherein said invertible sleeve includes reinforcement wires that run parallel to the stiff segment. 
     
     
         4 . A removable shunt according to  claim 1 , wherein said mechanism includes an introducer for a balloon to be inflated between the stent-graft and the aorta. 
     
     
         5 . A removable shunt according to  claim 1 , wherein said stiff segment is capable of withstanding compressive force of 1 kg per cm length without deforming inwardly more than 10%. 
     
     
         6 . A removable shunt according  1 , wherein said stiff segment has an outer diameter of 8 mm or less. 
     
     
         7 . A removable shunt according to  claim 1 , wherein said stiff segment has an outer diameter of 5 mm or more. 
     
     
         8 . A removable shunt according to  claim 1 , wherein said stiff segment has a length of 15 cm or more. 
     
     
         9 . A removable shunt according to  claim 1 , wherein said stiff segment has a length of 30 cm or less. 
     
     
         10 . A removable shunt according to  claim 1 , comprising a front segment that is moderately soft and deformable as not to injure the inside of the aorta, and not floppy, as not to fold or bend with the blood flow. 
     
     
         11 . A removable shunt according to  claim 1  wherein said mechanism includes a plurality of runners around the shunt. 
     
     
         12 . A removable shunt according to  claim 11  including a release mechanism for releasing said runners from one another. 
     
     
         13 . A kit comprising a removable shunt according to  claim 1 , and at least one additional device required for the deployment a stent-graft in a method according to  claim 1 . 
     
     
         14 . A method of deploying a branch stent graft having a tubular portion and a flared portion to connect to an aortic stent graft via the flaring portion, the method comprising first at least partially expanding the flaring portion; and thereafter expanding the tubular portion. 
     
     
         15 . A method according to  claim 14  comprising apposing the flaring portion against a luminal surface of the aortic stent graft so as to prevent leakage of blood between the flaring portion and the luminal surface. 
     
     
         16 . A method according to  claim 14 , wherein expanding the tubular portion is performed after said apposing. 
     
     
         17 . A method according to  claim 14 , wherein expanding the flaring portion comprises inflating a cuff. 
     
     
         18 . A method according to  claim 14 , comprising pressing the flaring portion against the luminal surface. 
     
     
         19 . A method according to  claim 18 , wherein pressing the flaring portion comprises expanding a flaring stent, such that when expanded, the stent presses a graft material of the flaring portion against a graft material of the aortic stent graft. 
     
     
         20 . A method according to  claim 19 , wherein the flaring stent is flaring from a tubular portion of the branch stent graft. 
     
     
         21 . A method according to  claim 14 , wherein inserting is with a delivery system comprising a fixer, fixing the branch stent graft to the delivery system, and the method comprises disabling the fixer after the pulling. 
     
     
         22 . A branch stent graft configured for attachment in a branched configuration to an aortic stent graft at an opening in a luminal surface defining a luminal space of the aortic stent graft, the branch stent graft comprising:
 (a) an expandable tubular stent graft; and   (b) an expandable flaring graft at an end of the tubular stent graft, said expandable flaring graft being configured to physically closely fit the luminal surface of the aortic stent graft at the peri-fenestration area when the flaring graft is expanded.   
     
     
         23 . A branch stent graft according to  claim 22 , wherein the expandable flaring graft is perpendicular to the tubular stent graft, when the expandable flaring graft is expanded. 
     
     
         24 . A branch stent graft according to  claim 22 , wherein the expandable flaring graft is configured to convexly expand as to follow concaveness of the surface that defines the luminal space of the aortic stent graft. 
     
     
         25 . A branch stent graft according to  claim 22 , wherein said tubular stent graft comprises a flaring stent portion configured to bias the flaring graft against the luminal surface of the aortic stent graft at the peri-fenestration area. 
     
     
         26 . A branch stent graft according to  claim 22 , comprising an inflatable cuff configured to bias the flaring graft against the aortic stent graft at the peri-fenestration area.