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.