Intravenous Tranexamic Acid reduces Blood Loss and Perioperative Transfusion Requirements in Multi-Level Thoracolumbosacral Posterior Spinal Fusion: A Standardized Inverse Probability Weighted Study

Introduction: The use of intravenous tranexamic acid (TXA) in spinal fusion has no established guidelines in spinal fusion. Its ability to decrease both intraoperative blood loss and perioperative blood transfusion requirements is under investigation. Determining its usefulness in complex spine surgeries is critical as the number of long segment posterior spinal fusions (PSF) in the adult spinal deformity (ASD) population increases.

Methods: Patients undergoing PSF in our institutional complex spine database were identified. Inclusion criteria were patients with PSF of ≥ 6 vertebrae, thoracolumbosacral region, adult population, and diagnosis of ASD. Demographics, baseline, preoperative, surgical, and postoperative characteristics were extracted. Utilizing covariates, including age, gender, race, BMI, Charlson Comorbidity Index (CCI), ASA score, number of PSF levels fused, 3-column osteotomy (3CO) use, and posterior column osteotomy (PCO) use, propensity scores were calculated and standardized inverse probability of treatment weighting (SIPTW) with subsequent frequentist statistical analysis was performed. Additionally, a subgroup analysis with multinomial SIPTW was conducted to elucidate associations between variables.

Results: Of 598 patients included in our analysis, 257 (42.98%) were in the TXA group and 341 in the non-TXA (control) group. Before balancing, the groups differed in age, gender, preoperative hemoglobin, BMI, ASA scores, osteotomy use, levels osteotomies, levels PSF, and CCI score (SMD>0.1). After SIPTW all baseline characteristics were appropriately balanced below the SMD threshold of 0.1. Weighted analysis revealed significant decrease in EBL in mL (p=0.002), intraoperative RBC transfusion in mL (p=0.021), postoperative RBC transfusion in mL (p=0.027), and postoperative pulmonary complications (p=0.031) in the treatment group. Subgroup analysis revealed significantly longer OR time (p=0.02) and decreased EBL in mL (0.026) in the group (n=143) receiving bolus and continuous infusion.

Conclusion : TXA demonstrated significant associations with reduced EBL, perioperative RBC transfusion requirements, and postoperative pulmonary complications in multilevel thoracolumbosacral PSF for ASD.