Impact of intraoperative blood loss on postoperative morbidity after liver resection for primary and secondary liver cancer

Background We sought to determine the association between intraoperative blood loss (IBL) and postoperative morbidity among patients undergoing surgery for liver cancer. Methods Patients undergoing surgery for primary and secondary liver cancer were identified from a multi-institutional database. Adjusted blood loss (aBL) was calculated by normalizing IBL to body weight; the comprehensive complication index (CCI) was used to evaluate postoperative complications. Results A total of 2491 patients were included. Mean CCI was 10.6 (+/- 5.2) for patients with aBL <10 mL/kg versus 15.2 (+/- 7.2) for individuals with aBL >= 10 mL/kg (p < 0.001). On cubic spline regression, a nonlinear correlation between aBL and CCI was observed. CCI increased exponentially for aBL ranging from 5 to 10 mL/kg, then reached a plateau between an aBL of 10-30 mL/kg before dramatically increasing for aBL >30 mL/kg. Recursive partitioning technique demonstrated that an aBL threshold of 8.5 mL/kg best distinguished CCI (p < 0.001). Additionally, patients with an aBL >= 8.5 mL/kg had worse recurrence-free and overall survival versus patients with an aBL <8.5 mL/kg. Conclusion A nonlinear incremental correlation between aBL and CCI was identified among patients undergoing surgery for liver cancer. Maintaining an aBL <8.5 mL/kg during LR may help reduce postoperative morbidity.