Double sheath deployment system

A stent-graft deployment system, comprising:

• a stent-graft;
• a catheter, comprising:
• a flexible catheter tip attached to a catheter shaft;
• a retractable primary sheath containing said stent-graft in a first constrained small diameter configuration around said catheter shaft near said flexible tip;
• a flexible secondary sheath disposed within said retractable primary sheath and also containing said stent-graft, wherein when said primary sheath is removed from around said stent-graft, said flexible secondary sheath contains said stent-graft in a second constrained small diameter configuration around said catheter shaft near said flexible tip, wherein removal of the secondary sheath releases the stent-graft from a radial constraint so that stent-graft deployment may proceed.

A stent-graft deployment system, comprising:

• a semi-rigid sheath;
• a flexible secondary sheath coaxially arranged within the semi-rigid sheath when the semi-rigid sheath is in a non-retracted position;
• a stent-graft collapsed within the flexible secondary sheath;
• an arrangement for retracting the semi-rigid sheath and exposing the flexible secondary sheath;
• a second arrangement for retracting the flexible secondary sheath, wherein the stent-graft is able to expand towards complete deployment as the flexible secondary sheath is retracted.

A method of deploying a stent-graft using a stent-graft deployment system having a retractable primary sheath and a secondary sheath within the primary sheath, comprises the steps of:

• providing the stent-graft deployment system with a stent-graft;
• tracking the stent-graft deployment system over a guide wire to a location before a target area, wherein the target area may include a curved portion;
• retracting the primary sheath to expose the secondary sheath containing the stent graft;
• moving the secondary sheath containing the stent-graft to a location within the target area;
• and
• retracting the secondary sheath to at least partially deploy the stent-graft in the target area.