A new aortic prosthesis (SAP, shape memory aortic prosthesis) was developed with its transfemoral placement system to treat aortic dissection with minimal invasion. The SAP consists of a Nitinol stent and polyurethane tube, and it is designed in such a configuration that it can be compressed inside a 14 Fr catheter when cold. It regains its original shape when warmed to 30 degrees C. From the results of intra-aortic sutureless placement of SAP in 10 mongrel dogs, we concluded that a SAP of proper diameter could be implanted safely for more than 3 months. The transfemoral placement system is composed of a delivery catheter, pushing rod, catching catheter, and pulling wire. Using these devices, transfemoral placement of SAP was demonstrated successfully in three dogs and one sheep. The original SAP and delivery system can be used as an emergency procedure for aortic dissections, such as Stanford type B. The advantages of the procedure are minimal invasion of acutely ill patients and prompt application in the catheter laboratory.