System and method for the sequential expansion of a medical device

A stent graft deployment system comprising:

• a delivery device having an operator end and a deployment end;
• a stent graft disposed at the deployment end, the stent graft having a proximal end nearest the deployment end, a distal end toward the operator end, a generally tubular structure, a length, a covered proximal end stent at the proximal end of the stent graft, a covered distal end stent at the distal end of the stent graft, and at least two intermediate stents between the covered proximal end stent and the covered distal end stent;
• a plurality of releasable constraining mechanisms arranged along the length of the stent graft, wherein at least one of the plurality of constraining mechanisms extends circumferentially about a portion of each of the covered proximal end stent, the covered distal end stent, and each of the at least two intermediate stents to hold the covered proximal end stent, the covered distal end stent and the at least two intermediate stents in a constrained configuration;
• and
• an actuation mechanism including a plurality of release wires or rods coupled to the constraining mechanisms to form a plurality of couplings between the release wires or rods and the constraining mechanisms about the circumference of the constraining mechanisms;
• wherein the release wires or rods are configured to be withdrawn to release the couplings between the release wires or rods and the constraining mechanisms of the proximal stent in stages circumferentially, and thereafter to release the couplings between the release wires or rods and the constraining mechanism of the at least one intermediate stent in stages circumferentially, and thereafter to release the couplings between the release wires or rods and the constraining mechanism of the distal stent in stages circumferentially, such that the proximal stent, the at least one intermediate stent and the distal stent are each expanded in stages about their circumferences and longitudinally from the proximal end of the stent graft to the distal end of the stent graft.

A method for deploying a stent graft in stages, comprising:

• introducing a delivery device to a deployment region of a body vessel,
• the delivery device having an operator end, a deployment end, a stent graft disposed at the deployment end, the stent graft having a proximal end nearest the deployment end, a distal end toward the operator end, a generally tubular structure, a length, a proximal end stent at the proximal end of the stent graft, a distal end stent at the distal end of the stent graft, and at least one intermediate stent between the proximal end stent and the distal end stent, a plurality of releasable constraining mechanisms arranged along the length of the stent graft, wherein at least one of the plurality of constraining mechanisms extends circumferentially about a portion of each of the proximal end stent, the distal end stent, and the at least one intermediate stent to hold the proximal end stent, the distal end stent and the at least one intermediate stent in a constrained configuration, and an actuation mechanism including a plurality of release wires or rods coupled to the constraining mechanisms to form a plurality of couplings between the release wires or rods and the constraining mechanisms about the circumference of the proximal end stent, the distal end stent;
• withdrawing the release wires or rods in a direction from the deployment end to the operator end;
• releasing the couplings between the release wires or rods and the constraining mechanisms of the first stent in stages circumferentially, and thereafter releasing the couplings between the release wires or rods and the constraining mechanism of the at least one intermediate stent in stages circumferentially, and thereafter releasing the couplings between the release wires or rods and the constraining mechanism of the distal stent in stages circumferentially, such that the proximal stent, the at least one intermediate stent and the distal stent are each expanded in stages about their circumferences and longitudinally from the proximal end of the stent graft to the distal end of the stent graft.