Introduction: Acute cholecystitis (AC) is the most common biliary stone disease complication. While there is consensus regarding cholecystectomy for AC, gallbladder drainage is indicated in elderly or high-risk surgical patients.
Evidence acquisition: We systematically reviewed available evidence in the field of EUS-guided gallbladder drainage (EUS-GBD) for AC in high-risk surgical patients. The studies were classified according to their level of evidence (LE) according to the Oxford Centre for Evidence Based Medicine classification.
Evidence synthesis: Literature search retrieved 175 manuscripts; most of them were expert opinions (LE V, N.=53) or case-series (LE IV, N.=29). There was no meta-analysis of RCT (LE Ia), while two randomized controlled trials (LE Ib) demonstrated that EUS-GBD was superior to percutaneous transhepatic-GBD (PT-GBD) regarding long-term outcomes (adverse events, recurrent cholecystitis, and reintervention). Several meta-analyses of cohort studies (LE IIa, N.=11) were designed to compare the three available drainage strategies (endoscopic, echoendoscopic and percutaneous) and to assess the pooled risk of adverse events. Comparison between surgery and EUS-GBD was done in a single retrospective study with a propensity score analysis (LE III). The outcomes of conversion from PT-GBD to EUS-GBD were covered by few retrospective studies (LE III). Several manuscripts (N.=69) were published on EUS-GBD as a rescue strategy in case of malignant biliary obstruction.
Conclusions: The levels of evidence of EUS-GBD in the literature have evolved from initial descriptive studies to recent randomized controlled trials and meta-analysis of cohort studies. While several articles addressed the comparison among different techniques for GBD, in our opinion some topics and questions have not been adequately investigated. are still debated.