Outcomes associated with bilateral plastic versus metal stents for palliation in malignant hilar biliary obstruction: an updated meta-analysis from the United States

Background/Aims: Endoscopic methods are favorable for palliation of malignant hilar biliary obstruction (MHBO) given its minimally invasive nature. This meta-analysis aimed to evaluate outcomes related to bilateral plastic stents (PS) versus bilateral metal stents (MS) in MHBO palliation.Methods: Databases were searched through November 2023. Only studies that directly compared bilateral PS and bilateral MS in MHBO were included. The primary outcome was clinical success. Secondary outcomes included technical success, adverse events, postprocedural cholangitis, recurrent biliary obstruction, endoscopic reintervention, and conversion to percutaneous drainage. Mantel-Haenszel pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using a random-effects model. Statistical heterogeneity was assessed using the I2 statistic and publication bias was assessed using funnel plots.Results: One randomized controlled trial and three retrospective cohort studies involving 420 patients were included. Bilateral MS had non-significant superior clinical success, lower rates of reintervention, and lower rates of adverse events, including postprocedural cholangitis. There was no difference in technical success or need for external drainage. Bilateral PS had increased odds of recurrent biliary obstruction (pooled OR, 1.79; 95% CI, 1.15-2.81; p=0.01).Conclusions: The selection of bilateral PS or MS for MHBO palliation should remain an individualized decision.