Stent placement above the sphincter of Oddi is a useful option for patients with inoperable malignant hilar biliary obstruction.

Abstract

Endoscopic biliary drainage (EBD) is essential for the management of malignant hilar biliary obstruction (MHBO). We prospectively evaluated the efficacy and safety of "inside-stent" therapy, where a plastic stent is placed above the sphincter of Oddi without endoscopic sphincterotomy, in patients with inoperable MHBO. This study was a multicenter, single-blinded, randomized controlled trial at three centers. Patients with inoperable MHBO were enrolled in this study, and randomly assigned to receive an inside-stent or conventional-stent therapy. The primary endpoint was cumulative stent patency of the initial stent. The secondary endpoints were second stent patency, technical and clinical success rate, adverse events, re-intervention rate, and overall patient survival. Forty-three patients were randomly assigned to the inside-stent group (n = 21) or the conventional-stent group (n = 22). The median cumulative stent patency of the initial stent was 123days in the inside-stent group and 51days in the conventional-stent group (P = .031). For patients with the initial stent dysfunction in the conventional-stent group, the inside-stent was placed as a second stent, and its patency was significantly longer than that of the initial stent (P = .0001). The technical and clinical success rate, re-intervention rate, second stent patency, adverse events, and survival probability did not differ between the groups. Inside-stent therapy appears to be useful not only as an initial stent but also as a second stent for patients with inoperable MHBO. UMIN000004587.