Anterior Exposure of the Left Posterior Lateral Segment of the Male Liver

Description

Anterior exposure targets Couinaud segment II of the left hepatic lobe, the left posterolateral (posterior lateral) segment that sits superior and lateral to segment III and lateral to the falciform ligament’s attachment. From the front, the diaphragmatic surface dominates, with the superior margin approaching the bare area and the left coronary ligament, while the inferior border tapers toward the left triangular ligament. Segment II lies left of the middle hepatic vein territory and, although the portal structures are deeper, its vascular supply typically derives from the left portal vein and left hepatic artery branches. Segmental anatomy matters because resections and ablations are planned by Couinaud divisions, not by surface lobes. Segment II lesions, including hepatocellular carcinoma, colorectal metastases, or focal nodular hyperplasia, often require careful planning to preserve the left hepatic vein and avoid marginal ischemia of adjacent segment III when performing a segment II resection or a left lateral sectionectomy (segments II and III). This anterior perspective also helps communicate how a posterolateral segment can still be accessed from an anterior approach once the left lobe is mobilized by dividing the left triangular and coronary ligaments. Clean landmarks. Fewer surprises. Common use cases include hepatobiliary surgery atlases illustrating left lateral sectionectomy, radiology teaching files that map CT or MRI findings to Couinaud segment II, and anatomy courses covering liver surface anatomy alongside functional segmentation. It also fits well in patient education materials explaining why a “left lobe” mass may be described more precisely as a segment II lesion. Anatomical accuracy verified by SciePro's Medical Advisory Board.