Study design: Retrospective review of intraoperative blood loss and blood replacement.
Objective: We compared intraoperative blood loss and blood replacement during spinal fusion surgery for scoliosis in Duchenne muscular dystrophy (DMD) performed with and without the synthetic antifibrinolytic agent tranexamic acid (TXA).
Summary of background data: High levels of intraoperative blood loss are widely documented in DMD patients undergoing posterior spinal fusion for scoliosis. The effect of the antifibrinolytic agent tranexamic acid on decreasing the blood loss has not been studied in a large group of DMD patients.
Methods: All 56 DMD patients underwent posterior spinal fusion with the same technique using 2 rods and multiple sublaminar wires. TXA was not used in 36 patients and was used in 20. In the respective groups, the age at surgery (14 vs. 13.9 years), the preoperative deformity (45 degrees vs. 51 degrees ), the mean number of levels fused (14.3 vs. 14.7), and the mean surgical times (446 minutes vs. 459 minutes) were similar. TXA dose was 100 mg/kg in solution over 15 minutes before incision followed by an infusion of 10 mg/kg per hour during surgery. Standardized measurements of intraoperative blood loss were used and calculated to compare total amount of blood loss in milliliters per patient and blood loss as a percentage in relation to estimated blood volume [estimated blood loss (EBL)/estimated blood volume (EBV) x 100]. The EBV was calculated to be 70 mL/kg (body weight).
Results: Mean blood loss with TXA was 1944 +/- 789 mL (range, 760-4000 mL) and without TXA was 3382 +/- 1795 mL (range, 600-9580 mL) (P < 0.001). Blood loss with TXA decreased by 42% compared with those not treated with TXA. Accounting for patient weight and estimated blood volume, mean % blood loss with and without TXA was 47% +/- 28% versus 112% +/- 67% (P < 0.001). This physiologic indicator shows that blood loss with TXA decreased by 58% compared with those patients not treated with TXA. TXA was also found to reduce blood loss after accounting for surgical time. No hypercoagulation or other complications from TXA therapy were observed. The reduced blood loss in TXA-treated patients translated into decreased blood transfusions. Transfusion of homologous whole blood and packed red blood cells in the TXA group was decreased by 46% compared with the no TXA group (mean levels, 512 +/- 470 mL vs. 955 +/- 718 mL), and transfusion of autologous cell saver blood was decreased by 42% in the TXA group (mean levels, 419 +/- 235 mL vs. 728 +/- 416 mL).
Conclusion: TXA significantly reduces both intraoperative blood loss and the need for homologous transfusion of whole blood and packed red blood cells in DMD patients undergoing posterior spinal fusion for scoliosis.