Can we safely reduce blood loss during lumbar pedicle subtraction osteotomy procedures using tranexamic acid or aprotinin?

Study Design: Retrospective, observational study. Objective: To compare the safety and efficacy of 2 pharmaceutical antifibrinolytic agents, aprotinin and tranexamic acid, in controlling blood loss during lumbar pedicle subtraction osteotomy (PSO) in adults. Summary of Background Data: Reconstructive spinal surgeries, in particular lumbar PSOs, have been associated with large blood losses despite interventions (intraoperative blood salvaging, controlled hypotensive anesthesia). Since the 1990s, intraoperative administration of antifibrinolytics (aprotinin, tranexamic acid, e-aminocaproic acid) has gained popularity. This study assesses the safety and efficacy of 2 antifibrinolytics, aprotinin and tranexamic acid, during adult lumbar PSO procedures at one institution. Methods: A retrospective comparative analysis of 44 consecutive adults undergoing posterior spinal fusion procedures with lumbar PSO at one institution was performed. Patients were analyzed according to treatment group: controls (10), aprotinin (14), and tranexamic acid (20). There were no significant differences in demographic (gender, age, comorbidities) or surgical traits (length of surgery, levels fused/exposed, preoperative hematocrit, bone graft source, primary/revision) between the 3 groups. Results: The aprotinin group had significantly less intraoperative blood loss (1114 ± 992 mL; P < 0.01)than the tranexamic acid and control group (2102 ± 1076 mL and 2260 ± 1580 mL, respectively). The aprotinin group received significantly less blood (577 ± 806 mL; P < 0.002) during the surgical procedure than the tranexamic acid (1838 ± 1096 mL) and the control group (1502 ± 1241 mL). There were no major intraoperative complications for any of the treatment groups. There were no postoperative cases of seizures, MI, CVA, DVT, or PE with any of the treatment groups. There was one acute tubular necrosis event in the aprotinin group, which resolved before discharge but did required several days of dialysis. Conclusion: The aprotinin treatment group lost significantly less blood and received significantly fewer blood transfusions than both the tranexamic acid and control groups without significant differences in intra- and postoperative complications. These results may justify further study of aprotinin and other antifibrinolytics for this specific indication (3-column lumbar osteotomies in the adult spinal deformity population). A multicenter randomized comparative analysis would be ideal.