Can tranexamic acid conserve blood and save operative time in spinal surgeries? A meta-analysis

Background context: It is widely accepted that tranexamic acid (TXA) effectively reduces blood losses and transfusions in major surgeries. However, limited studies investigated the role of TXA in conserving blood and saving operative time in spine surgeries.

Purpose: This meta-analysis was conducted to gather scientific evidence for TXA efficacy on conserving blood and saving operative time in spine surgeries.

Study design: A meta-analysis was performed.

Patient sample: Eighteen RCTs and 18 non-RCT studies involving 2,572 patients were included in the final analyses, comparing the effectiveness of intravenous TXA with a placebo/no treatment group.

Outcome measures: Outcomes of interest included intraoperative, postoperative, and perioperative blood losses, allogeneic blood transfusion rates, cell salvage transfusion amounts, operative time, and the number of postoperative thrombosis events.

Methods: An exhaustive literature search was conducted in the MEDLINE and EMBASE databases from January 2000 through March 2017. Meta-analysis was performed using Review Manager (RevMan) version 5.0. For continuous outcomes, the means and standard deviations were pooled to a mean difference and 95% confidence interval (CI). Odds ratios (OR) and 95% CI were calculated for dichotomous outcomes. The quantity of heterogeneity was assessed using I² statistics. When there was no statistical evidence of substantial heterogeneity (I²≤50%), a fixed-effect model was adopted; otherwise, a random-effect model was chosen. Subgroup analysis was performed when more than three studies were included on one issue, based on low or high the dose of TXA. Beijing Talent Fund (2016) was received to support this work.

Results: Significantly reduced intraoperative (weighted mean difference [WMD]=-280.09.00, p<.00001), postoperative (WMD=-120.15, p<.00001), perioperative (WMD=-310.86, p<.00001) blood losses, cell salvage transfusion amount (WMD=-471.79, p=.01), perioperative transfusion rate (odds ratio [OR], 0.33 [0.17, 0.65], p=.001), and operative time (WMD=-4.69, p=.003) were observed in TXA group. Furthermore, subgroup analysis revealed that high-dose TXA could reduce both intraoperative-perioperative allogeneic transfusion rates and operative time, whereas low dose of the drug does not convey such effects.

Conclusions: With the most comprehensive literature inclusion up to the present, this meta-analysis suggests that intravenous TXA use constitutes an important measure for conserving blood and saving operative time in spinal surgeries. High-dose TXA significantly reduces intraoperative-perioperative allogeneic transfusion rates and operative time, whereas low-dose TXA does not convey such efficacies. Larger prospective trials are still required to define the optimal regimen and to confirm the safety of TXA use in such surgeries.