Predictors of intraoperative blood loss in bimaxillary orthognathic surgery: A retrospective multivariate analysis

The aim of this study was to investigate the relationship between patient demographics and hematological parameters and blood loss during orthognathic surgery. In addition, we investigated whether bone removal around the descending palatine artery (DPA), a procedure that has been widely applied in recent years, is associated with blood loss.

This retrospective study included patients who underwent bimaxillary orthognathic surgery in our hospital. The predictor variables included patient demographics (age, gender and body mass index [BMI]), hematological parameters (hemoglobin level [Hb] and platelet count [PLT]), and surgical factors (bone removal around the DPA). Associations between predictor variables and blood loss were assessed using Spearman rank correlation and the Mann-Whitney U test. Multiple linear regression analysis was performed to identify independent predictors of blood loss during surgery. The level of significance was set as P<0.05.

A total of 138 patients (95 women and 43 men; mean age, 24.1±7.1 years) were included. The mean operative time was 269.1±51.3 minutes, and the mean intraoperative blood loss was 277.0±220.4mL. BMI, preoperative Hb, and operative time were significantly correlated with blood loss (p<.05). Male patients experienced significantly greater blood loss than female patients (p<.05). After adjustment, BMI (B=19.5, p=.001), operative time (B=0.95, P=.010), and removal of bone around the DPA (B=92.8, P=.009) were independently associated with increased intraoperative blood loss.

The findings in this study are important for preoperative risk assessment, surgical planning, and ensuring patient safety in orthognathic surgery.