Newly designed stent for endoscopic bilateral stent-in-stent placement of metallic stents in patients with malignant hilar biliary strictures: multicenter prospective feasibility study (with videos)

Background: Endoscopic management of malignant hilar biliary strictures is difficult even for an experienced endoscopist. Moreover, endoscopic placement of bilateral metal stents is considered very difficult and complicated. Objective: We explored the feasibility and efficacy of the placement of a newly designed metal stent for an endoscopic bilateral stent-in-stent procedure for the management of malignant hilar biliary strictures. Design: Multicenter prospective feasibility study. Setting: Five academic tertiary referral Centers. Patients: Thirty-five patients with malignant hilar biliary strictures of Bismuth type II or higher were enrolled. Interventions: Bilateral stent placement by in endoscopic stent-in-stent procedure. Main Outcome Measurements: Technical Success, functional success, early and late complications, stent patency. Results: The overall technical success rate of the newly designed metal stent was 94.3% (33/35). The success rate of the stent-in-stent procedure in a single session was 82% (27/33) per protocol and 77% (27/35) as intent to treat. In cases in which the initial stent-in-stent procedure failed, patients underwent the endoscopic stent-in-stent procedure for contralateral stent placement at 2 days (6%, 2/33) or 4 days (12%, 4/33) after the initial stent placement. There was no percutaneous insertion of a contralateral stent in these patients. There was no stent-related early or late complication in an), enrolled patient. Functional success was 100% (33/33). Reintervention because of stent malfunction was 6% (2/33). These 2 patients showed sludge formation in the stent. During follow-up, there was no stent tumor ingrowth or overgrowth in the placed stent in any enrolled patient. According to the Kaplan-Meier analysis, median survival and stent patency were 180 clays and 150 clays, respectively. Limitations: An uncontrolled feasibility study with a small patient population and a limited follow-up period. Conclusion: The newly designed metal stent for the endoscopic bilateral stent-in-stent procedure may be feasible and effective for malignant hilar biliary strictures.