Patent ID: 7918880

Claim:
A self-expanding stent in combination with a delivery system for delivering and deploying the self-expanding stent comprising: a self-expanding stent, the stent having a distal end; an outer sheath adapted to hold the self-expanding stent in an interior space before deployment of the self-expanding stent, said outer sheath having a delivery position in which it constrains the self-expanding stent and a retracted position in which it is retracted from and releases the self-expanding stent; an inner sheath located within the outer sheath and adapted to be arranged about the self-expanding stent before deployment of the self-expanding stent, said inner sheath comprising a set of expandable elements, said inner sheath having an unexpanded position in which it is located within the outer sheath and an expanded position after the outer sheath has been retracted to its retracted position; wherein the expandable elements extend distally to the distal end of the self-expanding stent or distally beyond the distal end of the self-expanding stent when the inner sheath is in the unexpanded position and when the inner sheath is in the expanded position; an expandable pusher configured to abut a proximal end of the self-expanding stent, said expandable pusher having a contracted position in which it is held within the outer sheath when the outer sheath is in the delivery position and an expanded position to which it expands after the outer sheath has been retracted to its retracted position, wherein the expandable pusher comprises a set of pusher springs, wherein a distal end of the set of pusher springs abuts the proximal end of the self-expanding stent and extend proximally therefrom; wherein a portion of the set of pusher springs extends radially inward; a two-stage retraction mechanism coupled to the outer sheath and the inner sheath that proximally retracts the outer sheath and the inner sheath, the two-stage retraction mechanism being configured to retract the outer sheath fully before retracting the inner sheath; and wherein the set of pusher springs of the expandable pusher that abuts the proximal end of the self-expanding stent is configured to maintain the longitudinal position of the self-expanding stent during retraction of the inner sheath.