Abstract: A biosensor for monitoring pressure or other physical parameters at an aneurysm site is mountable to a tubular prosthesis that is expandable between contracted and enlarged conditions. A loop, having the biosensor attached thereto, is securable around the prosthesis. An apparatus is used to deliver the loop to an aneurysm site that includes a catheter having a connector on its distal end for detachably securing the loop thereto. The prosthesis is advanced in a contracted state to the aneurysm, and the apparatus, with the loop connected thereto, is advanced to the aneurysm site. The loop and the prosthesis are positioned coaxially with respect to one another, and the prosthesis is expanded towards its enlarged condition, thereby engaging the loop around the prosthesis and engaging the prosthesis with a wall of the blood vessel at the treatment site.