Efficacy and safety of tranexamic acid in bimaxillary orthognathic surgery: systematic review and network meta-analysis of randomized controlled trials.

Bimaxillary orthognathic surgery often involves significant blood loss, requiring haemostatic control, which may include pharmacological interventions. Tranexamic acid (TXA) is widely used for this purpose; however uncertainty remains regarding its safety and optimal dosage. This systematic review and network meta-analysis was performed to evaluate the efficacy of intravenous TXA in reducing blood loss and transfusion need, and its safety in terms of thromboembolic risk. Randomized controlled trials (RCTs) comparing intravenous TXA at various doses and with placebo in bimaxillary procedures with quantitative outcomes were included. PubMed, Cochrane Library, Embase, Scopus, and Web of Science were searched, without language restriction, until April 2025. Risk of bias was assessed with the RoB 2.0 tool and certainty with the GRADE approach. The data were synthesized using a Bayesian model with surface under the cumulative ranking curve (SUCRA) classification. Five RCTs involving 353 participants were included. Only the 20 mg/kg dose of TXA was found to significantly reduce intraoperative blood loss compared to placebo. While the 10 and 15 mg/kg doses showed a reduction in blood loss, this was not statistically significant. No significant reduction in transfusion compared to placebo was observed, although SUCRA ranked the 2000 mg dose as most promising. No significant difference in thromboembolism risk was observed between the regimens. Intravenous TXA at 10-20 mg/kg appears to be effective and safe, with 20 mg/kg appearing most promising. However, the methodological heterogeneity and limited number of trials prevent any firm conclusions being drawn on the optimal dosage.