TTP6.09 A Cautionary Tale of Anatomical Variations of the Extrahepatic Biliary System and Their Implications for Surgical Procedures: A Systematic Literature Review

Aim Review published literature on the prevalence of extra-hepatic biliary system variations and their potential implications for surgical and endoscopic procedures. This will assist both practicing and trainee surgeons in preventing biliary tract injuries while operating in this area. Methods A systematic literature search was conducted on biomedical databases, using the PICO framework. Data from published studies relating to the prevalence, pattern and the distribution of extra-hepatic biliary system variations was collated. The prevalence of the most clinically important anatomical variations was computed and their implications during surgical/endoscopic procedures discussed. Results A total of 70 studies comprising 17207 subjects were selected for this systematic review. Low insertion, medial insertion and parallel course of the cystic duct occur in 11.2%, 9.8% and 7.4% of the population, respectively. Hartmann’s pouch of the gallbladder is present in 12.2%. The cystic artery arises from the right hepatic artery in 83.6% and from other variable origins in 16.4%. The Moynihan’s hump of the right hepatic artery is present in 1.8% of the population. Conclusion The hepatobiliary system has the most associated anatomical variations in the body and they are a direct reflection of the complexity of its embryological development. The anatomical pattern commonly described as ‘normal’ occurs only in 57 -72% of the population. These anatomical variations, although not significantly life-threatening like other anatomical variations, have significant clinical implications, as non-recognition and/or misidentification of normal anatomy and/or anatomical variations can result in the occurrence of major perioperative biliovascular complications