Delivery and release device for stent-graft

A delivery and release device for stent-graft, comprising:

• a guiding head, in the shape of a cone, and provided with a hollow passage formed axially therein;
• a central tube, one end of which is fixedly connected to a larger end of the guiding head and communicated with the hollow passage of the guiding head;
• an outer tube, sleeving on the exterior of the central tube, and operable to slide along the exterior of the central tube;
• a fixator, sheathed between the central tube and the outer tube, with an outer periphery of the central tube close to the larger end of the guiding head sheathed by the fixator, and with an outer periphery of the fixator coordinating with an inner periphery of the outer tube in a sliding manner;
• a positioning mechanism, adapted for positioning the stent-graft, the positioning mechanism comprises a positioning tube and a positioner, the positioning tube is sheathed between the fixator and the central tube and extends through the fixator, the positioner is sheathed between the positioning tube and the outer tube, with an outer periphery of the positioning tube at a rear side of the stent-graft sheathed by the positioner, and with an outer periphery of the positioner coordinating with an inner periphery of the outer tube in a sliding manner;
• an outer tube displacement regulating mechanism, sleeving on an outer periphery of the outer tube at an operation side, and adapted for controlling the axial movement of the outer tube;
• a central tube displacement regulating mechanism, sleeving on the central tube at an operation side, and adapted for controlling the axial movement of the central tube;
• wherein,
• the fixator comprises a front fixator and a back fixator, the front fixator and the back fixator are sheathed between the positioning tube and the outer tube respectively at the front side and at the rear side, the back fixator is provided with a conical anti-rotation member at its rear end for preventing the stent-graft from rotating, the conical anti-rotation member is sheathed between the positioning tube and the outer tube, and a plurality of anti-rotation recesses are formed axially on an outer periphery of the conical anti-rotation member,
• a tightening and releasing means for the stent-graft, comprises a flexible tightening member and a releasing member,
• the releasing member includes a plurality of metal bars fixedly connected and distributed in a circumferential manner on the end face of the larger end of the guiding head, and each of the metal bars extends in a direction parallel to the axial direction of the central tube,
• the flexible tightening member includes a plurality of ring sutures, and each of the ring sutures passes through a bare stent at the proximal end of the stent-graft and has one loop end fixedly connected on the front fixator and the other loop end detachably connected to a corresponding one of said metal bars,
• in a tightened state, the plurality of metal bars engage the plurality of ring sutures to tighten the bare stent at the proximal end of the stent-graft in a radially inward direction, and
• the central tube is operable to control the guiding head and the plurality of metal bars fixedly connected thereon to move forward in the axial direction of the central tube, to drive the plurality of metal bars to detach from the plurality of ring sutures and cause the plurality of ring sutures to detach from the bare stent, thereby releasing the bare stent at proximal end of the stent-graft.