Abstract: An apposition sensing system including a stent; a catheter assembly to which the stent is coupled for deployment into a lumen; and a sensor positioned on the catheter assembly adjacent to an end of the stent. The sensor is adapted to provide an electrical parameter which is indicative of apposition of the end of the stent to the inner wall of the lumen. In one aspect of the invention, the sensor includes first and second pressure sensors positioned at proximal and distal portions of the catheter assembly adjacent to proximal and distal ends of the stent. A monitoring unit monitors pressure changes sensed by the sensors. In accordance with an alternative embodiment of the invention, there is provided an expansion sensing system including a stent having an electrically conductive region; an expandable insulating sleeve; a catheter assembly to which the stent is coupled for deployment into a lumen; and at least one electrode associated with the catheter assembly.