Combined side‐by‐side and stent‐in‐stent method for triple metal stenting in patients with malignant hilar biliary obstruction

Background and Aim Endoscopic placement of three branched self‐expandable metallic stents ( SEMS ) for high‐grade malignant hilar biliary obstruction ( MHBO ) is technically challenging. We examined the feasibility and efficacy of a novel stenting method combining side‐by‐side and stent‐in‐stent ( SBSIS ) placement for MHBO . Methods Between January 2015 and December 2018, 27 consecutive patients with high‐grade MHBO underwent SBSIS placement. We evaluated the technical success, functional success, recurrent biliary obstruction ( RBO ), adverse events other than RBO , and reintervention success rates associated with SBSIS placement. Results Technical success rate was 85% (23/27). Insertion of the third SEMS failed in four patients, and median diameter of the common bile duct ( CBD ) was significantly smaller in patients in whom technical failure occurred (5 mm vs 8 mm; P  = 0.004). Functional success was achieved in all patients in whom the procedure was a technical success. Rate of adverse events other than RBO was 15% (4/27). RBO rate was 43% (10/23), and median time to RBO was 157 days. Success rate of endoscopic reintervention for RBO was 89% (8/9). Conclusion SBSIS placement showed favorable results and is a promising option in patients with high‐grade MHBO requiring triple metal stenting. However, it might be preferable to avoid SBSIS in patients with a narrow CBD . Clinical Trial Registry: UMIN000035721