Safety and efficacy of side-by-side versus stent-in-stent stenting for malignant hilar biliary obstruction: a systematic review and meta-analysis.

Objectives: Stenting of the malignant hilar biliary obstruction (MHBO) area for bile drainage is challenging. Bilateral stenting techniques of stent-in-stent (SIS) and stent-by-stent (SBS) have shown promising results. This study evaluates the efficacy of different stenting methods for MHBO.

Design: A meta-analysis was performed to determine the efficacy of SIS and SBS stenting strategies for MHBO.

Data sources and methods: Medical databases such as PubMed, Web of Science, Embase, and Scopus, were searched up to August 2023. We selected eligible studies reporting the data on technical and clinical success, adverse events, and incidence of re-obstruction (RO) of SBS and SIS groups in MHBO patients. We compared the outcomes of SBS and SIS groups.

Results: A total of 9 studies comparing the data of 545 patients (268 in the SBS group and 277 in the SIS stenting group) were analyzed. There was no significant difference (p > 0.05) in the odds ratio (OR) of Re-obstruction (RO) 0.87 (95% confidence interval (95% CI) 0.6-1.25), technical success 0.58 (95% CI 0.16-2.11), clinical success 1.13 (95% CI 0.62-2.07), and adverse events 1.53 (95% CI 0.88-2.64). The mean difference in procedure time was -12.25 min (95% CI -18.39, -6.12), and the hazard ratio of stent patency was 1.22 (95% CI 1.01-1.47), favoring SBS, with high heterogeneity (I ² = 94%). There was no significant difference in HR for survival 1.05 (95% CI 0.95-1.16) with high heterogeneity (I ² = 84%).

Conclusion: Compared with SIS, SBS showed better stent patency with comparable technical and clinical success and adverse events.

Prospero registration: The registration number for this study on PROSPERO is CRD42024523230.