A NEWLY-DESIGNED SHAPE-MEMORY COIL STENT FOR ESOPHAGEAL STRICTURE - APRELIMINARY-REPORT

A newly designed coil esophageal endoprosthesis was developed using a thermal shape-memory titanium-nickel alloy. The major advantages of th is stent lie in (a) its small diameter while in its compressed state i n ice water and (b) the large lumen which is achieved once it has been warmed to body temperature. The technical feasibility and tissue comp atibility of this stent mere tested on four beagle dogs: two with an a nastomotic stricture and two with a stenosis induced by the injection of monoethanolamine oleate. The teflon-coated stent was inserted under fluoroscopy and removed 4 weeks after implantation. No signs of esoph ageal reobstruction were observed in any of the animals after implanta tion or extraction of the stent, although the dog which had received t he first stent without teflon coating developed obstruction caused by granulation tissue. Our preliminary experience strongly suggests that the shape-memory alloy stent with teflon coating mag be used in the en doscopic treatment of anastomotic stenosis after esophagectomy, as wel l as of esophageal obstruction caused by carcinoma.