Gefäß- und Segmentanatomie der Leber: ein Vergleich des Lebersegmentmodells nach Couinaud mit einer patientenindividuellen computergestützten Segmentanalyse an portalvenösen Computertomogrammen der Leber.

The purpose of this study is to compare two methods for a segmental division of the liver. Segments are the smallest functional unit of the liver, which are independent in their blood supply. The boundaries of these segments are not visible at liver surface. Since the end of 19 century anatomical models have been established to provide an approximative visualization of the segmental division using anatomical landmarks. Claude Couinaud described a method to divide the segmental anatomy of the liver using a numbering of segments from I to VIII, which is widely accepted. Segmental anatomy is very important for liver surgery. Preoperative evaluation of the individual segmental anatomy is desirable. A segmental division of the liver relying on a model-based method is only an inexact compromise. According to this point a new computer-aided method based on the mathematical theory of fractal geometry has been developed using volume datasets provided by CT or MRI. This automatical method allows an individual division and three-dimensional visualisation of the hepatic segmental and vascular anatomy. Using the individual segmental hepatic anatomy and the volumetry provided by this new method, an exact preoperative intervention planning is possible. 35 CTAP datasets underwent examination in comparison of Couinaud’s model of liver segments with the new computer-aided analysis of liver anatomy. Results: A constant ramification of the portal vein has been observed according to the results from literature. The confluence of hepatic veins on the other hands showed great variability mainly at the left vein. In contrast the intrahepatic course of the hepatic veins showed a greater variability of the right hepatic vein than the left one. These results correlate to the examination of the maximal distances between the segmental boundaries of both applied methods showing the greatest variations in the part of the right hemiliver. Variations in segmental volume and the course of the segmental boundaries have more often been observed on behalf of the right hemiliver. The computer-aided segmental analysis is a practical method providing wavy segmental boundaries, which are known for anatomical studies. It seems to be the coming golden standard in segmental division of the liver. Yet, anatomical validation of the method has to be done.