Prosthesis delivery device with a pusher extension and an extension dilator

A method for treating a diseased vessel comprising;

• providing a prosthesis delivery device comprising a pusher catheter having a proximal end;
• a pusher extension extending proximally from the proximal end of the pusher catheter;
• a tubular prosthesis releasably coupled to the pusher extension, wherein the tubular prosthesis comprises a main tubular body having a proximal end and a distal end and a tubular side arm extending from the main tubular body and wherein the distal end of the tubular prosthesis is adjacent to the proximal end of the pusher catheter;
• wherein the pusher extension is external to the tubular prosthesis and extends along an external surface of the tubular prosthesis;
• an extension dilator having a lumen, the extension dilator extending proximally from the proximal end of the pusher catheter, extending at least partially along an external surface of the main tubular body, into a distal end of the tubular side arm and exiting a proximal end of the tubular prosthesis;
• a delivery sheath having a first position in which a proximal end of the sheath frictionally engages the extension dilator at a location proximal to the proximal end of the prosthesis and a second distally retracted position,
• tracking the delivery device over a guide wire within a patient's vasculature to position the prosthesis in a main vessel with the tubular side arm adjacent an opening to a branch vessel, wherein the guide wire extends through the lumen of the extension dilator;
• retracting the sheath to move it from the first position to the second position to expose at least the proximal end of the stent graft and the tubular side arm;
• withdrawing the extension dilator from the vasculature through the proximal end of the prosthesis leaving the guide wire in place to facilitate cannulation of a branch vessel,
• tracking an auxiliary sheath over the guide wire into the proximal end of the prosthesis and through the lumen of the tubular side arm until a proximal end of the auxiliary sheath is located adjacent the opening of the branch vessel to facilitate cannulation of the branch vessel;
• delivering an extension prosthesis through the auxiliary sheath into the branch vessel, and
• deploying the tubular prosthesis and the extension prosthesis and removing the delivery device from the patient's vasculature.