Comparison of endoscopic bilateral metal stent drainage with plastic stents in the palliation of unresectable hilar biliary malignant strictures: Large multicenter study

Abstract

Background: Endoscopic stenting to manage malignant hilar biliary obstruction has no consensus regarding the optimal stenting strategy. In this multicenter study, we compared transpapillary parallel-style bilateral metal stenting with bilateral plastic stenting, and evaluated short- and long-term outcomes.

Methods: We recruited 262 consecutive patients (Bismuth classification types II-IV) who underwent either bilateral metal or plastic stenting as primary therapy at four tertiary centers. To overcome selection bias, we performed 1:1 propensity score matching. Our primary outcome was overall survival.

Results: After propensity score matching, each group comprised 96 patients, with no significant differences in any baseline characteristics. The median survival was significantly longer in the metal stenting group than in the plastic stenting group (7.2 months [95% CI 6.0-8.5] vs. 4.1 months [95% CI 2.9-5.3]; P = 0.015). The clinical success rates were significantly higher in the metal stenting group than in the plastic stenting group (99.0% vs. 71.9%, respectively; P < 0.001), and lower post-procedure cholangitis incidence (7.3% vs. 26.0%; P < 0.001), longer median symptom-free stent patency (9.2 months [95% CI 7.6-10.6] vs. 4.8 months [95% CI 4.2-5.3]; P < 0.001), and fewer total interventions (1.3 ± 0.6 vs. 2.0 ± 1.4; P < 0.001). In multivariate Cox analysis of the overall survival, metal stenting (HR 0.589, P = 0.002), hilar cholangiocarcinoma (HR 0.419, P = 0.009), and adjuvant treatment (HR 0.596, P = 0.006) were independent predictors of death.

Conclusions: Endoscopic therapy using bilateral metal stenting is superior to bilateral plastic stenting, with prolonged overall survival, higher clinical success, and longer stent patency in patients with advanced hilar biliary malignancies.

Keywords: bile duct neoplasms; endoscopic retrograde cholangiopancreatography; overall survival; propensity score matching; self-expandable metal stent; stent.