Tranexamic Acid Is Efficacious at Decreasing the Rate of Blood Loss in Adolescent Scoliosis Surgery: A Randomized Placebo-Controlled Trial.

BACKGROUND: Tranexamic acid (TXA) is an antifibrinolytic drug that reduces surgical blood loss. Evidence supporting its efficacy in surgery for adolescent idiopathic scoliosis is not robust. This trial was designed to validate the clinical efficacy of TXA in surgery for adolescent idiopathic scoliosis.

METHODS: This institutional review board-approved prospective double-blinded trial involved 111 patients with adolescent idiopathic scoliosis who were randomized to receive either a placebo or TXA (50-mg/kg loading dose and 10-mg/kg/h infusion). Power analysis indicated that 50 patients per group would provide power to detect a >20% difference in blood loss. Two-way analysis of variance (ANOVA) was applied to compare blood loss rates (slopes) using the group-by-time interaction F test.

RESULTS: The risk of clinically relevant blood loss (>20 mL/kg) was more than twice as high in the placebo group than in the TXA group (44% versus 21%, relative risk = 2.1, 95% confidence interval = 1.2 to 3.7). Compared with the placebo group, the TXA group had a 27% reduction in intraoperative blood loss, a significantly lower rate of intraoperative bleeding per hour (mean and standard deviation, 190 ± 73 versus 230 ± 80 mL, p = 0.01; F = 9.77, p < 0.001) and per fused spinal level (82 ± 32 versus 110 ± 40 mL, p < 0.001), less intraoperative blood loss (836 ± 373 versus 1,031 ± 484 mL, p = 0.02), and less postoperative bleeding (in the drain) (498 ± 228 versus 645 ± 318 mL, p = 0.009). Six patients who received a placebo and no patient who received TXA required an allogenic blood transfusion. No perioperative adverse events, including thromboembolic events or seizures, were observed. Three independent factors were predictive of blood loss: TXA administration, duration of surgery, and number of levels fused. Greater intraoperative blood loss was the only independent variable predictive of a longer hospital stay.

CONCLUSIONS: Use of TXA in patients undergoing surgery for adolescent idiopathic scoliosis significantly reduced blood loss, by 27%, compared with that in the placebo group. The rate of intraoperative blood loss per hour and per level fused and the amount of postoperative blood loss were significantly lower in the TXA group. More placebo-treated patients received allogenic blood. Patients with greater intraoperative blood loss spent a longer time in the hospital.

LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.