Suprapapillary stent-by-stent deployment using slim fully covered metal stents versus plastic stents for unresectable...

Biliary drainage is essential for patients with malignant hilar biliary obstruction (MHBO) to relieve obstructive jaundice and cholangitis and improve survival and quality of life. Uncovered metal stents (MS) are recommended for unresectable cases because of their superior duration of patency; however, their removal is technically difficult once an occlusion occurs. Plastic stents (PS) have regained attention owing to being easily removable, particularly as advances in antitumor therapies have led to prolonged survival and increased need for reintervention; however, their patency remains limited. Recently, slim fully covered MS (FCMS) have been reported to reduce the risk of side branch occlusion and may combine long-term patency with removability. This trial aims to evaluate the efficacy and safety of suprapapillary stent-by-stent (SBS) deployment of slim FCMS compared with PS deployment in patients with unresectable MHBO.

This is a multicenter, randomized, open-label, parallel-group study. Patients with unresectable MHBO classified as Bismuth type II or higher are eligible for inclusion. After informed consent is obtained, the patients will be randomized (1:1) to undergo suprapapillary SBS deployment (placement above the duodenal papilla) with either a slim FCMS or PS. The slim FCMS that will be used in this study have a 6-mm diameter, and both the FCMS and PS are equipped with a distal retrieval string to facilitate stent removal during reintervention. The primary endpoint is the rate of non-recurrent biliary obstruction (RBO) at 6 months following the intervention. Secondary endpoints include the time to RBO, overall survival, procedure success rate, clinical success rate, procedure time, adverse events, and reintervention outcomes. The target sample size is 70 patients (35 patients per group).

Suprapapillary SBS deployment using slim FCMS may provide longer stent patency while preserving the feasibility of reintervention, potentially establishing a new standard biliary drainage method for unresectable MHBO.

Japan Registry of Clinical Trials: jRCT1040250073 registered on August 5, 2025. ( https://jrct.mhlw.go.jp/en-latest-detail/jRCT1040250073 ).