Surgical anatomy of liver segment IV.

Classical studies of the anatomy of the liver have led to the wide practice of hepatic resection. The difficulties encountered in the course of either right hepatectomy enlarged to include segment IV or left hepatectomy are mainly related to the vascular relations of this liver segment. This paper presents a summary of data from the literature concerning segment IV of the liver, as well as the results of experimental study via an original technique of resin injection of the portal vasculature and biliary drainage of this segment. The relations of the portal pedicles of segment IV with the bile duct originating from the confluence of the ducts draining segments II and III and with the left paramedian branch of the portal vein are described. Knowledge of these anatomical relations is essential to the proper execution of major hepatectomy.