Drainage patterns of right and accessory hepatic veins: anatomical-functional classification derived from 3-dimensional CT reconstructions.

BACKGROUND/AIMS: Inadequate knowledge of the right (RHV) and accessory (IHV) hepatic 'venous drainage' territories can lead to severe postoperative venous congestion after right graft live donor liver transplantation. The purpose of our study was to define the anatomical-functional RHV and IHV drainage territories. METHODOLOGY: One hundred and forty consecutive live liver donor candidates were evaluated by means of 3-D CT reconstructions and 3-D virtual hepatectomies. Three RHV/IHV drainage patterns were identified and 'risky' configurations for right graft resections were defined. RESULTS: Livers with 'small' IHV drainage volumes (90.1±63.2mL) had dominant type IRHV/ IHV or non-dominant type III-RHV/IHV total liver (TL) complexes. All other cases had 'large' IHV volumes (294.7±115.5mL, p<0.001) with dominant type II-RHV/IHV TL complexes. Loss of IHV drainage volume (such as with no IHV reconstruction) in these cases was associated with a 'dominance transition' from right (RHV) to middle (MHV) hepatic veins, placing the grafts at 'high risk' for venous congestion. CONCLUSIONS: Type II-RHV/IHV complexes with large IHV drainage volumes are at 'high risk' for venous congestion in live donor liver transplantation.