A new partially covered nitinol stent for palliative treatment of malignant bile duct obstruction: a multicenter single-arm prospective study

Background and study aims: Covered self-expanding metal stents (SEMSs) have proven effective for managing malignant bile duct strictures and may reduce risk of tumor ingrowth. A new nitinol partially covered biliary SEMS was prospectively evaluated. Patients and methods: 70 patients with inoperable extrahepatic biliary obstructions were enrolled in a prospective multicenter trial, and followed up to 6 months or death, whichever came first. Primary endpoint was adequate palliation defined as absence of recurrent biliary obstruction from partly covered SEMS placement to end of follow-up. Results: Mean age of the patients was 69 years and 52% were men. Pancreatic carcinoma was present in 68%. One stent was placed in 67 patients, two patients received two, and in one patient a guide wire could not traverse the stricture. In 55% of patients the SEMS was inserted de novo and in 45% for exchange with a plastic stent. Technical success was 97%. At 6 months, 62% of patients were free of obstructive symptoms; compared with baseline the mean number of symptoms per patient was significantly reduced (3.1 at baseline, 0.6 at 6 months; P < 0.0001) and total bilirubin levels dropped by 73%. There were four cases of recurrent biliary obstruction, due to stent migration (2), tumor overgrowth (1), and sludge formation (1). Device-related complications included cholecystitis (3), right upper quadrant pain (1), and moderate pancreatitis (1). No tumor ingrowth was reported. Conclusions: This new partially covered nitinol SEMS is easily inserted, and safe and effective in the palliation of biliary obstruction secondary to malignant bile duct strictures.