Abstract Body (Do not enter title and authors here): Background: Cardiac surgery can often be associated with significant postoperative bleeding. This complication results from a combination of surgical trauma, cardiopulmonary bypass (CPB)-induced coagulopathy, and enhanced fibrinolytic activity, all of which contribute to increased morbidity and mortality. Tranexamic acid (TXA) can be administered as an antifibrinolytic agent to control bleeding. While intravenous TXA is effective, there are concerns about its neurotoxicity by ability to cross the blood-brain barrier.
Objective: This systematic review and meta-analysis aimed to evaluate the efficacy and safety of topical versus intravenous TXA in patients undergoing cardiac surgery.
Methods: PubMed, Embase, and Cochrane were searched from inception to March 2025 for randomized controlled trials (RCTs) comparing topical versus intravenous TXA in cardiac surgery patients. Primary outcomes included postoperative blood loss and seizure incidence. Secondary outcomes included blood product transfusion requirements, thromboembolic events, reoperation, all-cause mortality, and intensive care unit (ICU) stay. Data were pooled using a random effects model with 95% confidence intervals (CI). Risk ratios (RR) were calculated for dichotomous outcomes, and standardized mean differences (SMD) and incidence rate ratios (IRR) were calculated for continuous outcomes.
Results: Of 1430 potential articles, seven RCTs comprising 3617 patients met the inclusion criteria. No significant difference in postoperative blood loss was observed between the intravenous and topical administration routes (SMD -0.00 ml; 95% CI -0.24, 0.23; p=0.98; I2=0%). Topical TXA significantly reduced seizure (RR 0.34; 95% CI 0.12, 0.92; p=0.03; I2=0%), with an absolute risk reduction of 0.57% and a number needed to treat 175. No significant differences were found in blood product transfusion requirements (IRR 1.10; 95% CI 0.73, 1.65), thromboembolic events (RR 1.00; 95% CI 0.38, 2.69), reoperation (RR 0.94; 95% CI 0.21, 4.22), mortality (RR 1.18; 95% CI 0.53, 2.62), or ICU stay (SMD -0.02 days; 95% CI -0.27, 0.23). GRADE assessments rated evidence as moderate for seizures and very low for blood loss.
Conclusions: Topical TXA provides similar hemostatic efficacy to intravenous TXA in cardiac surgery while slightly reducing the risk of postoperative seizures. Future research should focus on investigating specific patient subgroups who might derive maximal benefit from this administration route.