The complete anatomy of the cystic duct: A meta-analysis with implications for hepatobiliary surgery

BACKGROUND: The aim of this meta-analysis was to systematically evaluate the available literature to establish pooled prevalence data for the morphometric and topographical characteristics of the cystic duct (CD). METHODS: A systematic search was performed across various major databases such as PubMed, ScienceDirect, Web of Science and Scopus. RESULTS: Finally, a total of 105 studies were included in this meta-analysis. The pooled mean diameter of the CD was found to be 4.21 mm (SE = 0.36). The pooled prevalence of a long CD was established to be 5.22% (95% CI: 2.56-8.70), whereas a short or absent CD was observed with a prevalence of 3.78% (95% CI: 2.54-5.26). The occurrence of a double CD was found to be 1.20% (95% CI: 0.40-2.37). The most common site of CD insertion into the common hepatic duct (CHD) was the lateral (right) aspect, with a pooled prevalence of 63.94% (95% CI: 53.54-73.73). The middle level of CD insertion into the CHD was the most frequently observed configuration, with a pooled prevalence of 65.33% (95% CI: 55.46-74.59). CONCLUSIONS: This meta-analysis confirms that the anatomy of the CD is characterized by substantial variability, involving its morphology as well as the pattern and level of its junction with the biliary tree. Although many anatomical variants remain clinically silent, they have important practical implications, as they increase the risk of misidentification of biliary structures and iappeatrogenic injury during surgical and endoscopic procedures. The findings emphasize the need for thorough awareness of possible CD configurations and meticulous technique during hepatobiliary interventions. Overall, the results of this study may support improved preoperative planning, surgical education, and patient safety in hepatobiliary practice.