Stent insertion for hilar cholangiocarcinoma: a meta-analysis of comparison between unilateral and bilateral stenting

Introduction
Metal stenting can be used as a primary treatment option for alleviating malignant hilar biliary obstruction (MHBO) symptoms. Although many studies have focused on the topic of unilateral or bilateral stenting for MHBO, there is a clear need for a study comparing these two stenting types in patients with a single type of cancer.  Aim: This meta-analysis was conducted to evaluate the relative clinical efficacy of unilateral and bilateral metal stent insertion for hilar cholangiocarcinoma (HCCA).

Material and methods
The PubMed, Embase, and Cochrane Library databases were searched to identify all relevant studies. This meta-analysis was conducted using RevMan v5.3.

Results
We initially identified 154 studies, seven of which were included in the final meta-analysis. These studies contained 524 HCCA patients treated by either unilateral (n = 215) or bilateral (n = 309) stent insertion. No significant differences were observed between groups in rates of technical success (OR = 0.93; 95% CI: 0.34–2.54, p = 0.88), clinical success (OR = 1.03; 95% CI: 0.49–2.15, p = 0.94), stent dysfunction (OR = 1.47; 95% CI: 0.91–2.39, p = 0.12), or survival (HR = 0.85; 95% CI: 0.50–1.42, p = 0.53). However, the unilateral group exhibited significantly lower complication rates (OR = 0.34; 95% CI: 0.13–0.88, p = 0.03). Significant heterogeneity was found in the endpoint of survival. Funnel plot analysis did not suggest any publication bias relating to the selected study endpoints.

Conclusions
Compared to bilateral metal stenting, unilateral metal stenting could provide a similar clinical efficacy for patients with HCCA with a lower complication rate.