The efficacy and safety of high versus low doses of intravenous intraoperative tranexamic acid during spinal fusion in patients with adolescent idiopathic scoliosis: a network meta-analysis of randomized controlled trials.

introductionPosterior spinal fusion (PSF) for adolescent idiopathic scoliosis entails notable bleeding and transfusion risk, yet optimal tranexamic acid dosing remains undefined. We conducted a network meta-analysis (NMA) comparing high dose, low dose, and no-TXA regimens in this setting.

methodsWe conducted a PROSPERO-registered NMA (CRD420251033929) of RCTs in AIS patients undergoing PSF. PubMed, CINAHL, EMBASE, reference lists, and grey literature were searched for trials comparing high dose (20-50 mg/kg load; 10-20 mg/kg/h infusion), low dose (10 mg/kg load; 1 mg/kg/h infusion), or no TXA. Outcomes were pooled using a random-effects model to produce mean differences for continuous data and relative risks for binary data.

resultsFive RCTs (n = 475) were included. Patients had a frequency-weighted average (FWA) (SD) age of 15.1 (1.5) years, preoperative Cobb angle of 58.0 (7.9)°, 10.4 (1.3) levels fused, and operative time of 186.9 (62.0) minutes. They were allocated to high-dose TXA (n = 184), low-dose TXA (n = 144), or no-TXA (n = 147) arms. The FWA total EBL was 787.3 (261.5) mL in the high-dose group, 705.3 (219.0) mL in the low-dose group, and 1016.3 (492.2) mL in controls. There was no significant difference in EBL between high- vs low-dose TXA (MD -98.3 mL [-646.9, 426.2]). In the NMA, high-dose TXA reduced total EBL by 319 mL (95% CI -818 to 133) and low-dose by 219 mL (95% CI -764 to 294) versus no TXA-an 81% probability that no TXA was worst strategy-though neither comparison reached statistical significance. When compared per fused level, High- and low-dose TXA reduced EBL per level by 38.2 mL (MD -38.2 [-86.3, 6.1]) and 29.5 mL (MD -29.5 [-85.2, 27.3]) versus no TXA, respectively, without statistical significance; however, the no-TXA arm had an 87% probability of being worst for EBL by level. The FWA EBL per level was 78.9 ± 6.3 mL, 78.2 ± 7.2 mL, and 116.3 ± 17.8 mL for high-dose, low-dose, and no-TXA groups (very low certainty). When compared by operative time, high and lowdose TXA reduced EBL per hour by 81.0 mL/h (MD -81.0 [-250.0, 80.5]) and 60.2 mL/h (MD -60.2 [-285.0, 160.0]) versus no TXA, respectively, with no statistical significance. FWA EBL per hour was 273.8 ± 112.6 mL/h, 315.4 ± 133.6 mL/h, and 249.8 ± 150.2 mL/h for high dose, low dose, and no TXA (very low certainty). Both TXA arms had no complications vs. one uncontrolled bleed in the no-TXA group (0.7%).

conclusionHigh and low dose TXA in AIS PSF yielded modest, non-significant reductions in total blood loss and per-level EBL. No thromboembolic, neurologic, or renal complications occurred among, underscoring its safety. These results support a case-by-case approach to TXA use and highlight the need for larger, standardized RCTs to confirm its clinical value.