3456 Treatment of benign intrahepatic duct stricture using polyurethane covered retrievable nithinol stent

Benign intrahepatic duct strictures are usually caused by intrahepatic stones or postoperative strictures, and optimal therapeutic strategy is not well established. The treatment using uncovered metal stent is not generally recommended because it is not removable and eventually occludes by tissue ingrowth and sludge or stone formation.We developed a new nithinol stent (Stentech, Seoul, Korea) which is covered by polyurethane membrane and has a draw-string at the end of stent allowing endoscopic removal. AIMS: This preliminary study was performed to evaluate the safety and usefulness of polyurethane covered retrievable nithinol stent in the treatment of benign intrahepatic stricture. METHODS: Nine patients (M:F=4:5, mean age 42±10 yrs) who had benign intrahepatic duct strictures due to intrahepatic stones (n=6) or postoperative hepaticojejunostomy site strictures (n=3) were included. Retrievable nithinol stents were inserted via percutaneous transhepatic tract after cholangioscopic examination and treatment. Plain abdominal X-ray and liver function test were checked at 1, 3, 5 days after stent insertion for the detection of stent migration and cholangitis. Then, abdominal ultrasonography and cholangioscopy as well as liver function test were checked at monthly interval. RESULTS: 1) The insertion and removal of the stents were successful in all patients. The diameter of stents was 10 mm and the stent lengths were 2-4 cm. 2) The stents were removed 6-8 weeks after insertion except 1 patient, who complained of abdominal pain and the stent was removed 2 weeks after insertion. 3) Stent migration was noted in 1 patient and the stent was exchanged. 4) Upon cholangioscopic examination, mucosal hyperplasia near the end of stent was noted in 2 patients and sludge formation at the inner surface of stent was noted in all patients, however, the occlusion of stent was not seen. 5) During median follow-up period of 257 days after stent removal (range: 151-328 days), restenosis of stricture was not noted. CONCLUSIONS: The insertion and removal of polyurethane covered nithinol stents seem to be safe and the dilation of strictures occur in a short period of time. Retrievable nithinol stent might offer an alternative treatment of benign intrahepatic duct strictures.