Stent delivery device with rolling stent retaining sheath

A delivery device, comprising:

• a stent device that is expandable from a radially reduced, delivery configuration to a radially expanded, deployed configuration;
• a retaining sheath disposed over the stent device for maintaining the stent device in the delivery configuration;
• a pull member to be pulled upon to retract the retaining sheath in such a manner that the retaining sheath is folded back on itself to provide a radially inner sheath of the retaining sheath, a radially outer sheath of the retaining sheath and a fold portion therebetween, wherein the pull member is moveable by pulling thereon to move the outer sheath over the inner sheath and thus to move the fold portion axially relative to the stent device to retract the retaining sheath from over the stent device to release the stent device for expansion to the deployed configuration, wherein the pull member is a pull line, and wherein
• the pull line extends axially along the stent device and joins the retaining sheath substantially at or beyond an axial end of the stent device in a pre-retracted configuration of the retaining sheath.