Cross‐wired metal stents for endoscopic bilateral stent‐in‐stent deployment in malignant hilar biliary obstruction: A multicenter, single‐arm, prospective study

OBJECTIVES: The endoscopic bilateral stent‐in‐stent (SIS) deployment is a challenging procedure. Such difficulty is mainly caused by sticking of the tip of the delivery sheath into the self‐expandable metal stents (SEMSs) mesh, requiring an additional dilating procedure. Herein, we assessed the clinical results of using cross‐wired metal stent for endoscopic bilateral SIS deployment (BONASTENT M‐Hilar) in patients with malignant hilar biliary obstruction (MHBO) in both high‐volume and non‐high‐volume centers. METHODS: We prospectively enrolled consecutive patients with MHBO between February 2016 and December 2018 at eight centers. RESULTS: Forty‐six patients were enrolled during the study period. The proportions of technical success were 93.5% (43/46) and clinical success (CS) on intention‐to‐treat and per‐protocol analyses were 91.3% (42/46) and 93.0% (40/43), respectively. The proportion of an additional dilating procedure during the primary procedure was 50.0% (23/46). Recurrent biliary obstruction (RBO) on intention‐to‐treat analysis occurred in 32.6% (15/46) of cases. Almost all of the events were caused by stent ingrowth (14/15). The median survival time and time to RBO were 255 and 349 days, respectively. The probability of stent patency at 3, 6, and 12 months was 86.5%, 63.9%, and 47.6%, respectively. CONCLUSIONS: The cross‐wired metal stent had excellent technical and CS, although non‐high‐volume centers were included in this study (UMIN000021441).