The effect of antifibrinolytic therapy on complications, blood product utilization, and fusion in adult spinal deformity

Abstract

Antifibrinolytic therapy (AF) has been shown to be effective in preventing blood loss in some settings. Its effect in patients undergoing adult spinal deformity (ASD) surgery remains unclear. This study looks at the use of antifibrinolytic therapy in adult spinal deformity surgery and its effect on major and minor perioperative complications, blood product utilization, vascular events and postoperative fusion. A multicenter prospective consecutive database of surgical ASD patients was reviewed. Complications were divided into intra-operative and perioperative (within 6 weeks). Parameters of blood product utilization included the rate of transfusion, and the units of PRBCs and FFP transfused. Thromboembolic events included stroke, deep venous thrombosis (DVT) and pulmonary embolus (PE). Fusion rates at 2 years were measured on AP and lateral radiographs at using the Lenke classification. The impact of AF use on complications, blood product utilization, vascular events and fusion rates was studied using multivariate logistic, ordinal logistic, or poisson regression, as appropriate. Models accounted for confounders as determined by univariate analysis and expert opinion. In total, 403 patients were included, 137 patients received aminocaproic acid (ACA), 81 received tranexamic acid (TXA), 185 received no AF, 227 patients had two-year radiographic data. The use of AF was associated with a decrease in transfusion (ACA OR 0.38 P = 0.043, TXA 0.31 P = 0.047), a decrease in the number of units of PRBCs transfused (ACA IRR 0.45 P = 0.0005, TXA IRR 0.7 P = 0.0005), and a decrease in the number of FFP transfused (ACA IRR 0.65 P = 0.003, TXA IRR 0.67 P = 0.006). The use of TXA (but not ACA) was associated with a decrease the incidence of major perioperative complications compared to no AF (IRR 0.37, P = 0.019). AF use was not associated with an increase in thromboembolic events. The use of AF did not impact the fusion rates at 2 years. The use of TXA or ACA was associated with increased minor intra-operative complications. TXA was associated with decreased major perioperative complications. AF was associated with decreased utilization of blood products without an increased rate of thromboembolic events. Given the observational nature of this study, transfusion threshold was not standardized across the study sites. Future studies with rigid criteria for transfusion should be prospectively performed to better evaluate AF use in ASD.