Vascular Anatomy of Segment IV of the Liver in Live Liver Donors

Background: Studies on the anatomy of the liver have helped surgeries such as liver resection. Liver resection is of significance in liver transplantation. In liver resection, the anatomy of segment IV is very important as it is more prone to ischemia. Aim: The primary objective is to study the anatomical variations of the hepatic artery and hepatic vein of segment IV from MDCT images of the hepatic vasculature in living liver donors. This study aims to document the anatomy of the hepatic artery supplying segment IV and its venous drainage in 300 living liver donors. Materials and methods: In this retrospective study, 600 MDCT images of hepatic vasculature were observed, and the interpretations were recorded. The origin of the artery to segment IV was documented. The observations of the hepatic vein were tabulated as classified in Nakamura’s study. Results: Segment IV artery originates from the left hepatic artery (LHA) in 72% of the cases and the right hepatic artery (RHA) in 23%. Hepatic venous drainage of segment IV comprises type I, type II, and type III in 14.33%, 53.67%, and 30% of cases, respectively. Type I anatomy of the hepatic vein is preferred in both right and left lobe liver transplantation as the drainage from segment IV is safe. Conclusion: Vascularity to segment IV is key in living liver donors, as donor safety is of utmost importance in the case of living donor liver transplantation.