Extrahepatic and Segmental Arterial Supply of The Human Liver and Their Clinical Implications: A Corrosion Cast Study.

Abstract

Introduction The arterial anatomy of the liver is highly variable with normal anatomy present in 50.7%-80.9% of cases. Recognition of abnormalities is of crucial importance during surgical and radiological interventions, especially in liver transplantation, because an impaired hepatic arterial blood supply may result in ischemic complications. The purpose of our study was to investigate the anatomical variations of the extra- and intrahepatic arterial structures of the liver with particular attention to rare variations and their surgical management. Materials and methods Fifty human abdominal organ complexes were used to prepare corrosion casts by applying a special multi-component resin mixture with CT density. Digestion was achieved by a solution of concentrated KOH at 60-65°C for one week. The preparations were analyzed macroscopically. The extrahepatic arterial variations were classified according to Michels and the arterial supply of liver segments were described. Digital pictures were taken of the vascular casts and 3D volumetric reconstructions were made of the unclassified cases. Results Normal anatomy was found only in 32%, whereas the unclassified group showed the second highest incidence: 30% (15/50), with 10 casts presenting arterial anatomy that have not been reported before. The arterial supply of the liver segments were described by the origins of their feeding arteries. We sequenced the different liver segments according to the variability of arterial supply. The caudate lobe showed the most variable patterns, we observed 49 different vascular structures in 50 cases; whereas segment VIII. received its segmental artery from the same root in 68% of cases. The unclassified variations underwent 3D CT imaging analysis and virtual hepatectomies were performed to demonstrate the optimal resection planes. Conclusion Significantly different frequencies of arterial variations were found in our series compared to other publications. We detected new variations including extrahepatic, segmental and combined patterns. Our data may contribute to the better understanding of the segmental arterial supply of the human liver and therefore lead to the reduction of complications during surgical interventions in the upper abdomen.