Utility of the inside stent as a preoperative biliary drainage method for patients with malignant perihilar biliary stricture.

Background/purpose Appropriate preoperative biliary drainage (PBD) is extremely important in patients with operable malignant perihilar biliary strictures. The aim of this study was to clarify the utility of inside stents in PBD. Methods Eighty-one patients with malignant perihilar biliary stricture who underwent endoscopic nasobiliary drainage (ENBD) as the first PBD method were enrolled. Biliary stenting was performed in 61 patients during the study course (41 patients; inside stent implanted in the bile duct, 20 patients; conventional stent placed across the papilla of Vater). Twenty patients continued ENBD until surgery. Treatment outcomes were compared among the three groups. Results The re-intervention rate was significantly lower in the inside stent group than in the conventional stent group and ENBD groups (9.8% vs. 40% and 35%, P = 0.013 and 0.030, respectively), and the time to re-intervention was also significantly longer (log-rank: P = 0.004 and 0.041, respectively). Of the five patients in the inside stent group who underwent neoadjuvant chemotherapy, only one required re-intervention. There was no significant difference in the incidence of postoperative complications among the three groups. Conclusions The inside stent may be a useful PBD method for patients with malignant perihilar biliary stricture.