A comparative study of the anatomy of rat and human livers.
ABSTRACT To compare the fundamental structure of the human liver, in relation to that of the rat a comparative study was performed, in which 20 rat livers and 78 human cadaver livers were examined. The rat livers had four lobes (left, middle, right, and caudate). The left and middle lobes formed a single lobe but the middle lobe had a deep notch to which the round ligament attached. The right lobe was split into two sub-lobes and the caudate lobe was divided into the paracaval portion and the Spiegel lobe, which was split into two sub-lobes. The left, right, and caudate lobes had one primary portal branch, whereas the middle lobe had two portal branches. The left and the right sub- and caudate lobes had one large hepatic vein each, whereas three large hepatic veins were observed in the middle lobe. Based on the ramifying patterns of the portal and hepatic veins, the rat middle lobe possessed left and right hepatic components and a main portal fissure. The following rat hepatic lobes were equivalent to the following human liver segments: the left lobe to segment II; the middle lobe to segments III, IV, V, and VIII; and the right lobe to segments VI and VII. The fundamental structures of rat and human livers were similar, and the findings demonstrated a new interpretation of the anatomy of the human liver.
Article: The paracaval segments of the liver[show abstract] [hide abstract]
ABSTRACT: Two segments constitute thedorsal sector: I to the left and in front of the inferior vena cava, and IX in front and to the right of the cava; they are united inferiorly by the caudate process. Segment I includes the caudate lobe, and segment IX is incorporated in the posterior surface of the right liver. Small dorsal pedicles, which are quite numerous, arise from the posterior margin of the main portal elements, and ascend upward. Segment I receives twigs from the left or right livers, many from the right lateral pedicle (67 biliary branches enter the right lateral duct, the unique duct in three cases). Segment IX consists of three subsegments. IXb lies under the interval between the middle and right superior hepatic veins, in 40% of the cases examined the veins come from the left portal vein or the bifurcation, in 6 cases the ducts enter the left hepatic duct, in 40 cases the branches extend higher than the plane of the main hepatic veins, in 18 cases reaching the upper surface of the liver. IXc is under the right hepatic vein, and IXd is to the right of a vertical plane passing by the right superior vein. Hepatic veins, enter the cava directly, sometimes the middle or the left hepatic veins.Journal of Hepato-Biliary-Pancreatic Surgery 01/1994; 1(2):145-151. · 1.60 Impact Factor