Impact of tranexamic acid on visualization in full endoscopic spine surgery: a randomized controlled trial

The aim of this study was to evaluate whether prophylactic administration of intravenous tranexamic acid (TXA) improves intraoperative visualization during full-endoscopic lumbar spine surgery for single-level degenerative disc herniation.

A prospective, randomized controlled trial was conducted including adult patients undergoing single-level, full-endoscopic lumbar discectomy. Participants were randomly allocated in a 1-to-1 ratio to receive either intravenous TXA (10 mg/kg, maximum 1 g) prior to anesthesia induction or standard care without TXA. Intraoperative visualization was assessed using a visual analog scale (VAS) and a 4-grade visualization scale by the operating surgeon and two independent evaluators, all of whom were blinded to group allocation. Secondary outcomes included operative parameters such as surgery duration, irrigation fluid volume, pump pressure, and the need to reduce blood pressure. An automated video analysis was performed to evaluate blood in the endoscopic field. Outcomes included a blood pixel ratio (BPR) and a derived visualization score (DVZ).

All 58 randomized participants completed the study. Visualization quality was high in both cohorts. The median surgeon-reported VAS was 8 (interquartile range [IQR] 6-9) in both the TXA and control groups (p = 0.4). Surgeon visual classifications were similar (p = 0.8), with "excellent" or "good" ratings reported in 72% of the TXA group and 79% of the control group. Independent evaluator VAS scores yielded equivalent medians of 8 (p = 0.6 for evaluator 1, p = 0.8 for evaluator 2). A univariate linear regression evaluating the treatment effect of TXA on the mean VAS score showed an estimated difference of -0.31 (95% CI -1.0 to 0.41; p = 0.57). The median DVZ (9.30 vs 9.22; p = 0.3) and the median BPR (3.55% vs 4.57%; p = 0.3) were similar in both groups. The median operative duration was 50 (IQR 40-65) minutes for TXA and 60 (IQR 45-70) minutes for controls (p = 0.2). No thromboembolic complications or TXA-related adverse events were observed.

Endoscopic lumbar discectomy offers good or excellent intraoperative visualization in most cases. This study did not demonstrate a significant improvement in intraoperative visualization with the prophylactic administration of intravenous TXA. While TXA appeared safe, its routine use specifically to enhance visual clarity in single-level endoscopic lumbar discectomy was not currently supported by these data.