Evaluation of a newly modified nonflared fully covered metal stent, 12 mm in diameter, for intraductal placement in patients with malignant biliary strictures: a feasibility study

Abstract

BACKGROUND AND STUDY AIM: The nonflared ends of fully covered, self-expandable, metal stents (FCSEMSs) may minimize stent-induced ductal injury. Suprapapillary intraductal placement of nonflared FCSEMSs for malignant biliary stricture might reduce duodenobiliary reflux and pancreatitis. The aim of this study was to evaluate the efficacy of a newly modified, nonflared FCSEMS for intraductal placement in patients with malignant biliary stricture. PATIENTS AND METHODS: A total of 51 patients with nonhilar, extrahepatic, malignant biliary stricture were enrolled prospectively. The nonflared FCSEMS is 12 mm in diameter, and has a central saddle and a distal lasso of 7 cm in length. An FCSEMS was placed above the papilla in all patients, with the central saddle positioned at the stricture to prevent stent migration. RESULTS: The technical and clinical success rates were 100 % and 98 %, respectively. Early adverse events occurred in one patient (2.0 %; mild pancreatitis). A total of 12 patients underwent surgery with curative intent, one of whom (8.3 %) experienced a postoperative adverse event. No stent migration occurred in any of the patients. Cholecystitis developed in one patient (2.0 %) as a late adverse event. Stent occlusion occurred in 44.7 % (17/38), and endoscopic removal of the stent was successful in 87.5 % of patients. The mean stent patency was 297 days (95 % confidence interval, 211 - 383). CONCLUSIONS: Intraductal placement of the nonflared FCSEMS, 12 mm in diameter, was feasible for the palliative and preoperative management of patients with malignant biliary stricture. Long-term follow-up and prospective comparative studies are needed to evaluate the usefulness of intraductal placement of this stent.