Patent ID: 8333686

Claim:
A cannula assembly, comprising: a cannula having an inner wall defining a lumen; and an insertion device including: (a) a shaft including a distal end, the shaft configured to be received within the lumen of the cannula; (b) a tip member coupled to the distal end of the shaft, the tip member configured to extend distally out from the lumen of the cannula so as to be in position for dilating a puncture in a tissue; (c) a compressible member operatively coupled to the shaft and configured to expand in a generally radially outward direction when compressed in an axial direction; wherein the compressible member is movable from an initial state in which the compressible member has a first radial dimension to a compressed state in which the compressible member has a second radial dimension that is larger than the first radial dimension, the second radial dimension configured to engage the inner wall of the lumen of the cannula to releasably secure the insertion device to the cannula.