The Concept of Anatomical Analogy Between the Liver and the Pancreas

Embryologically derived from foregut buds, the liver and pancreas are anatomically distinct and have discrete functions. However, for surgeons undertaking dedicated work in the hepato-pancreato-biliary region, realizing the analogy of their gross anatomy can be meaningful, even though it has not been widely noticed and discussed. In this article, we describe the anatomical similarities between these two organs, which can aid in performing certain forms of major hepatectomy and pancreatic resections. The pancreas comprises of a head with an uncinate process extension, a neck, a body, and a tail. The "C" loop formed by the neck, head, and the uncinate process of the pancreas encloses the superior mesenteric/portal vein (SMV/PV) and the superior mesenteric artery (SMA). The gross pancreas anatomy is similar to the gross anatomy of the liver. The right lobe of the liver extending to the caudate lobe (CL) is analogous to the head and the uncinate process, segment 4 is analogous to the neck of the pancreas, and the body/tail of the pancreas is analogous to the left lateral sector. Similar to the SMV and SMA, enclosed in the "C" loop of the pancreas, the common hepatic duct, portal vein, and right and left hepatic arteries are enclosed in the "C" loop of the liver, formed by segment 4, the right hemiliver, and the CL. The inferior vena cava and abdominal aorta are related to the posterior surface of the "C" loop of the right liver and pancreas. Our observation of the anatomical analogy between the pancreas and the liver can be used to simplify the teaching of gross anatomy, which could enhance understanding of the spatial anatomy of the liver and pancreas in an easy, faster, more memorable, and longer-lasting manner. The described anatomical analogies can also aid in conceptualizing and decoding the topographic complexities of major liver and pancreatic surgeries for budding and advanced surgeons.