Method and apparatus for delivery deployment and retrieval of a stent comprising shape-memory material

Claim 1

A stent delivery system comprising: a catheter having a first tube and a second tube, said first tube having a proximal end, a distal end and a first lumen and said second tube disposed concentrically within said first tube, the first lumen being defined by an annulus between said first and second tubes; a balloon sealingly connected to said first tube adjacent the distal end, the balloon defining an interior volume and having an exterior surface defining a stent engagement region, the interior volume of said balloon in communication with the first lumen; and a shape-memory alloy stent having been compressed at a temperature below a phase-change transition temperature of the stent material on said balloon in the stent engagement region of said balloon to a reduced diameter configuration, said stent having a phase-change transition temperature chosen to prevent expansion of the stent upon exposure to body temperature, such that upon pressurized introduction of a fluid having a temperature in excess of the phase-change transition temperature through the proximal end of said first lumen, the balloon is pressurized and heats said stent engagement region to cause the stent temperature to increase to undergo a phase-change transition to so cause the stent to expand to return to its austenite phase configuration, an expanded configuration which has a diameter substantially larger than said reduced diameter configuration, wherein the second tube defines a second lumen adapted for receiving a guidewire, said first tube further including a portion defining at least one aperture through the wall located proximally of said stent engagement region by which the heated fluid may exit the first tube and bathe the stent.