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 an 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 any 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 days and 150 days, 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.