Antifibrinolytic therapy in surgery for adolescent idiopathic scoliosis: Does the level 1 evidence translate to practice?

Introduction: Previous randomized controlled trials have demonstrated the efficacy of antifibrinolytic agents in the reduction of intraoperative blood loss in adolescent idiopathic scoliosis (AIS) surgery. Tranexamic acid (TXA) was found to be more effective at reducing total blood loss compared with epsilon-aminocaproic acid (AM) than placebo. We set out to study whether or not the level 1 evidence can be corroborated in a large multicenter, multisurgeon cohort. Methods: Estimated blood loss (EBL), cell saver transfused, and percent of total blood volume (%EBL) was retrospectively assessed from a prospective-collected multicenter AIS registry. Volume of allogeneic blood transfusion data was not uniformly available. The cohort was divided into: 1. TXA (N = 525; 2006-2014), 2. Amicar (N = 117; 2005-2014), and 3. no antifibrinolytic (N = 1127; 2005-2013) groups. Comparisons between the three groups and between antifibrinolytic (Amicar or TXA) versus no antifibrinolytic (NA) groups were performed using ANOVA with Bonferroni correction and the t-test, respectively. Multivariate analysis was used to control for surgical and surgeon factors. Results: EBL, %EBL, and cell saver transfused was significantly lower in TXA (742.3 mL, 21.3% and 191.8 mL, respectively) than NA (1,010.6 mL, 29.8% and 276.6 mL, respectively) and AM (1,420.6 mL, 38.9% and 456.0 mL, respectively), (p < 0.0001), with AM having the greatest values among the three groups. These parameters were normalized by number of levels fused and Cobb magnitude. A similar pattern was observed, with AM having the highest normalized values and TXA group the lowest among all three groups. After further controlling for surgeon, total operative time, and osteotomy performed, multivariable analysis revealed that EBL/level, %EBL/level, and cell saver/level transfused were significantly lower in the TXA group compared to the NA group (p = 0.0014, p = 0.0058, and p = 0.0031, respectively), whereas, no difference was observed between the AM and NA groups (p = 0.1028, p = 0.2523, and p = 0.5274, respectively). The differences between TXA and AM were diminished (p = 0.5512, p = 0.6751, and p = 0.0978, respectively). Conclusion: Intraoperative administration of TXA significantly reduces EBL, %EBL, and cell saver transfused during AIS surgery. After taking operative and surgeon factors into consideration, %EBL was not significantly different between TXA and Amicar groups in the practice setting.