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

BACKGROUND AND AIMS: 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.

METHODS

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.

RESULTS

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 123 days in the inside-stent group and 51 days 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.

CONCLUSIONS

Inside-stent therapy appears to be useful not only as an initial stent but also as a second stent for patients with inoperable MHBO.

TRIAL REGISTRATION NUMBER: UMIN000004587.