Figure 3.
Historical change of definition of the caudate lobe by Prof. Couinaud. (A), In 1989, the caudate lobe was divided into segments Il and Ir based on the spatial position. The boundary between the two segments is the plane connecting middle hepatic vein and inferior vena cava (7). By this time, Couinaud had proposed the idea to divide segment Ir into subsegments b, c and d, but the schema of segmentation was not shown. (B), In 1994, segment Ir was replaced by segment IX (8). By this time, Couinaud had proposed the idea to divide segment IX into subsegments b, c and d, but the schema of segmentation was not shown. (C), In 1998, the subsegments of IX were shown on the figure. The right hepatic vein runs between subsegments b and d (9). Subsegment IXc is located beneath the right hepatic vein. (D), In 2000, the subsegments b and d were replaced by subsegments IXL and IXR (10). The figures were modified from the original ones.