Relationship between hepatic venous anatomy and hepatic venous blood loss during hepatectomy

Predicting increased blood loss based on anatomical intervascular relationships is essential in major hepatectomy. We assessed 63 consecutive patients undergoing anatomical hepatectomy exposing the hepatic vein (HV) trunk at two institutes. Correlations between anatomical alterations of the hepatic inferior vena cava (IVC), HV, hepatic IVC, or right atrium (RA) and the blood loss per standard weight (BLSW) or blood transfusion (n = 18) were analyzed. The results of IVC partial clamping (PC) were additionally examined. The BLSW in type V-up anatomical morphology was significantly higher than that in straight type (p   13.5 mL/kg) were tumor size (> 4 cm), prothrombin activity (  7 mmHg), area of suprahepatic IVC (  28 mm), longitudinal angle of IVC (< 160°), and axial angle of the MHV (< 55°). A multivariate analysis revealed that a high IVC-RA gap was a significant independent risk factor (odds ratio; 4.32, p < 0.05). Among 25 patients undergoing IVC-PC, only three showed a remarkable decrease in hepatic venous bleeding. No other statistically significant differences in the surgical records were observed in most cases. The IVC-RA gap might be a promising novel predictive parameter reflecting increased blood loss leading to blood transfusion in anatomical hepatectomy.