Objective: Adequate biliary decompression is important in treating bile leaks, and endoscopic transpapillary drainage is widely used for this purpose. As an indicator to evaluate the usefulness of endoscopic drainage for postoperative biliary leakage, we focused on external drain removability, which affects quality of life, after endoscopic treatment. Our aim was to clarify the success rate of external tube removal after endoscopic drainage for postoperative biliary leakage and to examine associated factors.Methods: This was a multicenter retrospective study; 99 patients with biliary leakage at 13 institutions were enrolled between April 2014 and March 2019. Among these patients, 66 who were initially treated with endoscopic interventions for biliary leakage after cholecystectomy (n = 17) or hepatectomy (n = 49) were reviewed.Results: In post‐cholecystectomy biliary leakage, the external‐drain‐free rate at first endoscopic intervention was 100%, and the drains, including transpapillary stents, were successfully removed in almost all cases (16/17). In contrast, in post‐hepatectomy biliary leakage, the external‐drain‐free rate was 44.9% (22/49), with all 22 of those patients eventually becoming entirely drain‐free. A lower body mass index was the only significant factor associated with freedom from external drainage in post‐hepatectomy biliary leakage (odds ratio 0.18, 95% confidence interval 0.05–0.65).Conclusions: Initial endoscopic treatment was effective for post‐cholecystectomy biliary leakage, while approximately half of the patients with post‐hepatectomy biliary leakage required multidisciplinary management. Achieving freedom from external drainage contributes to patients’ quality of life and may be a predictor of treatment response after endoscopic therapy for postoperative biliary leakage.

Supplementary Figure 1. Bax deficiency suppresses hepatocyte apoptosis, liver regeneration and oxidative stress in the livers of Mcl-1 KO mice.

Supplementary Figure 3. Deep sequencing of almost all coding lesions of p53 and beta-catenin.

Supplementary Table 2. Gene lists called by VIrmed using whole exome sequencing data of tumor lesions and their surrounding non-tumor lesions in Mcl-1 KO mice.