Patent ID: 7731740

Claim:
A method for preparing an assembly for delivering a degradable and bioresorbable polymeric stent that is substantially resistant to negative recoil when expanded mechanically to a final predetermined diameter in a lumen of a tube, duct, or vessel of a mammalian subject, the method comprising the following steps in order: (a) heating a polymeric cylindrical device which is at a final predetermined diameter and wall thickness to a temperature sufficiently above the glass transition temperature (Tg) of the polymer and for a time sufficient to erase memory of previous processing of the polymeric cylindrical device, wherein the final predetermined diameter and wall thickness are substantially the same as the diameter and wall thickness of a stent that has been expanded to a final desired diameter at a target site in a tube, duct, or vessel of the mammalian subject, wherein the device is mounted on a solid support for maintaining the cylindrical device at the final predetermined diameter, and wherein the polymeric cylindrical device has a wall defining a first open end, a second open end, and a channel connecting the first and the second open end; (b) rapidly cooling the polymeric cylindrical device at a temperature below the Tg of the polymer to quench the polymeric cylindrical device and to provide an educated polymeric cylindrical device having a memory of the final predetermined diameter; (c) forming slits, voids, or open spaces in the wall of the polymeric cylindrical device prior to step (a) or after step (b), wherein the slits, voids, or open spaces are configured to allow a reduction in the diameter of the device without substantially altering the wall thickness of the device; (d) mounting the educated polymeric cylindrical device on an inflatable balloon catheter; (e) reducing the diameter of the cylindrical device by heating the cylindrical device to a temperature at or slightly above the Tg of the polymer while evenly applying pressure on the exterior surface of the wall of the cylindrical device; and (f) then rapidly cooling the cylindrical device below the Tg of the polymer to provide an assembly comprising a inflatable balloon catheter and an expandable polymeric stent which is substantially resistant to negative recoil when expanded mechanically to the final predetermined diameter by inflation of the balloon in the lumen of a tube, duct, or vessel of the mammalian subject or when expanded mechanically to the final predetermined diameter by inflation of the balloon and stored at 37° C. for 4 weeks or more.