PURPOSE Endoscopic bile duct decompression using bilateral self-expandable metallic stents (SEMSs) deployed via a stent-in-stent (SIS) method is considered a preferred procedure for malignant hilar biliary obstruction (MHBO). However, occlusion thereof occurs frequently. Here, we investigated stent patency duration and risk factors related to stent obstruction with bilateral SIS placement for MHBO at two large centers.

MATERIALS AND METHODS The present study reviewed data on patients with MHBO who underwent endoscopic biliary drainage using the SIS method. Clinical outcomes, including stent patency duration and patient overall survival, were analyzed. Factors associated with stent patency were evaluated using Cox proportional hazards models.

RESULTS Seventy patients with MHBO underwent endoscopic biliary drainage using the SIS method. Median age was 68 years old, and median follow-up duration was 140 days (interquartile range, 57-329). The proportion of high-grade MHBOs (Bismuth type IV) was 57.1%. Median stent patency duration with the SIS method was 108 days according to Kaplan-Meier curves. Median patient survival analyzed by the Kaplan-Meier method was 181 days. Multivariate analysis indicated that higher baseline bilirubin (> 6.1 mg/dL) as an independent risk factor related to stent patency (p<0.05).

CONCLUSION In endoscopic biliary decompression using SEMS placed with the SIS method, obstructive jaundice was a risk factor for stent patency. The SIS method for high-grade MHBO showed short stent patency.