A novel online calculator to predict perioperative blood transfusion in patients undergoing liver resection for hepatocellular carcinoma: an international multicenter study

Background: To develop an easy-to-use model to predict the probability of perioperative blood transfusion (PBT) in patients undergoing liver resection for hepatocellular carcinoma (HCC). Method: 878 patients from Eastern Hepatobiliary Surgery Hospital of Shanghai were enrolled in the training cohort, while 691 patients from Tongji Hospital of Wuhan and 364 patients from two hospitals from Europe and America served as the Eastern and Western external validation cohorts, respectively. Independent predictors of PBT were identified and used for the nomogram construction. The predictive performance of the model was assessed using the concordance index (C-index) and calibration plot, and externally validated using the two independent cohorts. This model was compared with four currently available prediction risk scores. Results: Eight preoperative variables were identified as independent predictors of PBT, which were incorporated into the new nomogram model, with a C-index of 0.833 and a well-fitted calibration plot. The nomogram performed well on the externally Eastern and Western validation cohorts (C-indexes: 0.786 and 0.777). The discriminatory ability of the nomogram was superior to the four currently available prediction scores (C-indexes: 0.833 vs. 0.671-0.770). The nomogram was programmed into an online calculator, which is available at http://www.asapcalculate.top/Cal3_en.html. Conclusion: A nomogram model, using an easy-to-access website, can be used to calculate the PBT risk and identify which patients undergoing HCC resection are at high risks of PBT and can benefit most by using blood conservation techniques.