13. Clinical efficacy of tranexamic acid in posterolateral lumbar fusion: a prospective, randomized controlled trial

Abstract

BACKGROUND CONTEXT Tranexamic acid (TXA) has been increasingly used to decrease blood loss during a large variety of surgical procedures, including joint arthroplasty and spinal deformity procedures. However, TXA is not routinely used in degenerative lumbar spine cases, and the optimal dosing regimen for these cases is not known. PURPOSE The purpose of this study was to explore the clinical utility of TXA in open posterior lumbar fusions (PLF) while comparing intravenous and oral dosing regimens. STUDY DESIGN/SETTING Prospective randomized controlled trial. PATIENT SAMPLE Patients indicated for open posterior lumbar fusion for degenerative pathology by one of three fellowship-trained spine surgeons were recruited for the study. Patients with procedures that included 4 or more levels, or those who had a current/recent history of thromboembolic events, allergy to TXA, and/or pregnancy were excluded. OUTCOME MEASURES Outcome measures assessed were postoperative reduction in hemoglobin and hematocrit, blood transfusion rate, calculated blood loss, and complications. METHODS Patients were randomized to one of four study arms: 1) oral placebo, 2) intravenous TXA at time of incision, 3) 1950mg oral TXA 1 hour before incision, and 4) 1950mg oral TXA 1 hour before incision, and 1950mg oral TXA once per day for three days after surgery. Differences between study arms were assessed using a combination of chi-square & ANOVA for categorical and continuous data, respectively. The threshold for statistical significance was set at p RESULTS A total of 79 patients (44/79; 55.7% female) were enrolled, with a mean age of 64.9±12.2 years, body mass index of 32.3±6.2 kg/m2, and an average of 1.9±1.4 vertebral levels fused. For each treatment group, 21, 19, 20, and 19 patients were assigned to study arms 1-4, respectively. There were no differences in baseline demographic or operative characteristics. Patients across the entire cohort had a mean postoperative reduction in hemoglobin and hematocrit of -3.2±1.4 g/dL and -9.8±4.2 %, respectively, with an associated 1999.2±841.9 ml of calculated blood lost. Four patients experienced postoperative anemia (Group 1: 2/19, 10.5%; Group 4: 2/17, 11.8%) requiring a blood transfusion of 2 units each. No patients experienced other serious hospital complications such as postoperative epidural hematoma formation, pulmonary embolism, deep vein thrombosis, or stroke. There were no significant differences between groups in postoperative reduction in hemoglobin and hematocrit, blood transfusion rate, calculated blood loss, or complications. Similarly, there were no differences in assessed outcomes between patients who received any form of TXA when compared to placebo. CONCLUSIONS TXA can be used safely in PLF, though there was no clear benefit in hemostasis when compared to placebo, and outcomes did not vary based on dosing regimen. These preliminary findings suggest that TXA may not have a clinically meaningful application in short-length open PLF. FDA DEVICE/DRUG STATUS TXA: Investigational.