Stent insertion with high-intensity focused ultrasound ablation for malignant biliary obstruction: A protocol of systematic review and meta-analysis

BACKGROUND This meta-analysis was conducted in order to understand the clinical efficacy of stent insertion with high-intensity focused ultrasound (HIFU) ablation for the treatment of malignant biliary obstruction (MBO). METHODS The Pubmed, Embase, and Cochrane Library databases were searched for all relevant studies published through July 2020. The meta-analysis was conducted using RevMan v5.3, with analyzed study endpoints including the rate of stent dysfunction, time to stent dysfunction, stent patency, complication rate, and overall survival (OS). RESULTS In total, 35 potentially relevant studies were initially identified, of which 6 were ultimately included in the present meta-analysis. These 6 studies included 429 MBO patients that were treated either only via stenting (n = 221) or via stenting in combination with HIFU ablation (n = 208). Pooled stent dysfunction rates in the stent and stent with HIFU groups were 25.9% and 18.0%, respectively (OR: 1.59; 95% CI: 0.88, 2.84, P = .12). The average time to stent dysfunction was significantly longer in the stent with HIFU group relative to the stent group (MD: -3.15; 95% CI: -3.53, -2.77, P < .0001). Pooled complication rates in the stent and stent with HIFU groups were 17.1% and 19.6%, respectively (OR: 0.88; 95% CI: 0.49, 1.58, P = .67). Stent patency and OS were both significantly longer in the stent with HIFU group relative to the stent group (P < .0001 and.0001, respectively). Funnel plot analyses did not reveal any significant evidence of publication bias linked to the selected study endpoints. CONCLUSIONS This meta-analysis found that a combined stenting and HIFU ablation approach can achieve better stent patency and OS in MBO patients relative to stent insertion alone.