Abstract: An apparatus includes a flexible tubular member containing a shape-memory tube formed to include a lumen extending along the central axis of the tubular member. A liner sleeve extends through the lumen of the shape-memory tube and lies inside the tubular member. A control system selectively heats the shape-memory tube to its activated state causing the shape-memory tube to move toward a predetermined shape if it is different than its present configuration. Whether the shape-memory tube moves or not, it will increase significantly in stiffness, both axial and bending to help retain, hold, or wedge the apparatus in place in a selected body cavity while catheters or other objects are passed through a lumen in the liner sleeve.

Abstract: An apparatus includes a flexible, elongated tubular member and a tube arranged to lie inside the tubular member. The tube has a lumen extending along the central axis of the tubular member. In one embodiment, the tube is made of a temperature-activated shape memory metal. In another embodiment, the tube is made of superelastic nitinol.