Definitive Posterior Survey of the Male Liver Fissure for Ligamentum Teres

Description

Seen from a caudal, posterior oblique survey, the inferior surface of the liver is oriented so the sagittal umbilical fissure (fissure for ligamentum teres hepatis) is readable as a deep groove within the left sagittal fissure. The fissure runs anteroinferiorly toward the umbilical region, where the fibrous round ligament occupies the fossa as a remnant of the fetal vena umbilicalis. Medial to it lies the porta hepatis region and the fissure for the ligamentum venosum extends superiorly toward the left hepatic vein, while lateral parenchyma corresponds to the left lobe surface. Clean landmarks. This posterior perspective matters because the ligamentum teres and its sulcus provide a dependable separator between segment III (left lateral inferior) and segment IVb (left medial inferior) in Couinaud segmentation, which is how many hepatobiliary surgeons plan a left hepatectomy or segmentectomy. It also frames the course of paraumbilical veins, which can recanalize in portal hypertension and enlarge within or adjacent to the umbilical fissure, creating a potential pitfall on CT or MRI when distinguishing a true fissure from a mass effect. The caudal angle emphasizes the relationship of the umbilical groove to the visceral surface and adjacent fissures used during intraoperative orientation. Use this illustration in gross anatomy and hepatobiliary modules when teaching the left sagittal fissure, the round ligament (ligamentum teres), and their continuity with the obliterated umbilical vein. It also fits atlases, surgical textbooks, and radiology teaching files that discuss Couinaud segments, portal hypertension collaterals, and surface landmarks for the porta hepatis. Anatomical accuracy verified by SciePro's Medical Advisory Board.