Protocol for a systematic review of the management and outcomes in patients with gallbladder agenesis

Gallbladder agenesis (GA) is a congenital anomaly of the biliary system, with characteristic absence of the gallbladder and cystic duct often with variable clinical presentation. Despite major advances in imaging technology many patients undergo unnecessary operative interventions during which the diagnosis is made. Very little is known on the management and outcomes in this patient population. Therefore, the main objective of this study protocol is to guide a comprehensive review of published cases of GA to evaluate and synthesize research findings on its presentation, management and clinical outcomes. This systematic review will be conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols guidelines. MEDLINE, via PubMed, EMBASE, SCOPUS and Google Scholar will be searched for articles on GA in humans (case report and case series) published before 1 October 2022 in English, French and Spanish. Two independent investigators will review each article, determine if it meets inclusion criteria, extract data and assess the study quality. A third investigator will arbitrate studies where there are conflicts between the first two investigators. Short and long-term outcomes will be compared between cases that underwent non-operative versus open versus laparoscopic surgery. Estimates will be made of odds ratios for dichotomous outcomes.