Vertical interval between hepatic segment of inferior vena cava and right atrium predicts intraoperative blood loss during hemi-hepatectomy.

Intraoperative bleeding is a major issue for hepatic surgeons because large intraoperative blood loss causes poor patient outcome. The aim of this study was to identify predictors of intraoperative bleeding during hemi-hepatectomy. Methods This study enrolled 45 living donors for liver transplantation (cohort 1) and 44 patients with various conditions (cohort 2) who underwent hemi-hepatectomy at Ehime University Hospital between January 2010 and March 2019 (Approval number: 1810024). The gap between the ventral horizontal line of the inferior vena cava (IVC) confluent with the right atrium (RA) and the dorsal horizontal line of the hepatic segment of the IVC (IVC-RA gap) was determined from preoperative images. Cardiopulmonary and liver functions were investigated as potential predictors of intraoperative estimated blood loss (iEBL). Results The IVC-RA gap positively correlated with iEBL in cohorts 1 and 2 (r = 0.453, P = 0.002 and r = 0.443, P = 0.003, respectively), and multivariate analysis selected the IVC-RA gap as an independent predictor of iEBL >400 ml in cohorts 1 and 2 (odds ratios 1.177 and 1.115; 95% confidence intervals 1.041-1.330 and 1.007-1.234; P = 0.009 and P = 0.036, respectively). Conclusions The IVC-RA gap is a novel and simple predictor of iEBL.