Relationship between Variant Biliary and Vascular Anatomy in Living Liver Donors in Pakistani Population

Abstract

Objective: To investigate the relationship of variant biliary anatomy with hepatic vascular variants in living liver donors. Methods: A retrospective cross-sectional study was conducted at Shifa International Hospital, Islamabad, from January 2017 to Feb 2020. Two radiologists reviewed pre-operative Computed tomography (CT) angiography and Magnetic resonance cholangiopancreatography (MRCP) of live liver donors having the variant biliary anatomy only, in consensus. The classification of the conventional or variant hepatic artery, hepatic veins, and portal vein was done based on CT angiography scans, while biliary anatomy was characterized based on MRCP images. Results: Of 165 liver donors with variant biliary anatomy, standard anatomy involving hepatic arteries observed in 88 (53.3%) and portal veins in 125 (75.8%) individuals. Twenty-nine (17.5%) liver donors had trifurcation pattern (B) and 26 (15.7%) had short right hepatic duct (C). Forty (24.2%) had anterior right hepatic duct (RAHD) continuing into common hepatic duct (D). In 49 (29.6%) donors, abnormal right posterior hepatic duct (RPHD) configurations draining into left hepatic duct (E) were found. In 21 (12.7%), RAHD had separate drainage into left hepatic duct (F). Trifurcation, short right hepatic artery, drainage of RPHD into left hepatic duct, and drainage of RAHD into left hepatic duct were mostly observed in conventional-Michel's I, i.e., 16 (9.7%), 12 (7.2%), 28 (16.9%), 14 (5.4%), and 88 (53.3%) respectively. Conclusion: Among the biliary variants, type D and E were most frequent. There was also an increased incidence of a concurrent variant hepatic arterial supply in liver donors in presence of variant biliary drainage.