Anterior Perspective of the Male Liver's Anterior Medial Segment

Description

Anterior hepatic parenchyma is presented from an anterior perspective with emphasis on the anterior medial segment, classically Couinaud segment IV (often described as IVa superior and IVb inferior) within the left hepatic lobe. Medially, this segment lies adjacent to the fissure for the ligamentum teres and the falciform ligament, while laterally it approaches the plane separating it from the left lateral segments (II and III). Inferiorly, its border relates to the visceral margin near the gallbladder fossa and the anterior edge of the liver. Segmental boundaries are implied by portal venous distribution rather than surface grooves. For hepatobiliary surgeons and interventional radiologists, segment IV matters because it sits at the crossroads of left and right inflow and frequently enters operative planning for left hepatectomy, extended left hepatectomy, and central resections. Tumors near the middle hepatic vein or the umbilical fissure can force a balance between oncologic margins and preservation of functional remnant liver, and segment IV is a common area where that tradeoff becomes explicit. Mislabeling segment IV as segment V is a persistent teaching error. This view helps correct that. Use this artwork in gross anatomy teaching (liver surface anatomy and peritoneal reflections), surgical atlases illustrating Couinaud segmentation, and journal figures for hepatic resection planning or ablation targeting in hepatocellular carcinoma and colorectal liver metastases. It also fits patient-facing education on liver lobes and segments when paired with CT or MRI diagrams. Anatomical accuracy verified by SciePro's Medical Advisory Board.