Portal Supply and Venous Drainage of the Caudate Lobe in the Healthy Human Liver: Virtual Three-Dimensional Computed Tomography Volume Study.

OBJECTIVE: The venous vascular anatomy of the caudate lobe is exceptional. The purpose of this study was to assess portal inflow and venous outflow volumes of the caudate lobe.

METHODS: Extrahepatic (provided by the first-order branches) versus intrahepatic (provided by the second- to third-order branches) portal inflow, as well as direct (via Spieghel veins) versus indirect (via hepatic veins) venous drainage patterns were analyzed in virtual 3-D liver maps in 140 potential live liver donors.

RESULTS: The caudate lobe has a greater intrahepatic than extrahepatic portal inflow volume (mean 55 ± 26 vs. 45 ± 26%: p = 0.0763), and a greater extrahepatic than intrahepatic venous drainage (mean 54-61 vs. 39-46%). Intrahepatic drainage based on mean estimated values showed the following distribution: middle > inferior (accessory) > right > left hepatic vein.

CONCLUSIONS: Sacrifice of extrahepatic caudate portal branches can be compensated by the intrahepatic portal supply. The dominant outflow via Spieghel veins and the negligible role of left hepatic vein in caudate venous drainage may suggest reconstruction of caudate outflow via Spieghel veins in instances of extended left hemiliver live donation not inclusive of the middle hepatic vein. The anatomical data and the real implication for living donors must be further verified by clinical studies.