The effect of Amicar on perioperative blood loss in idiopathic scoliosis: The results of a prospective, randomized double-blind study

Study Design. A prospective, randomized, double-blind Institutional Review Board- approved study evaluating the efficacy of Amicar ( epsilon aminocaproic acid), an antifibrinolytic agent, in decreasing perioperative blood loss in idiopathic scoliosis. Objectives. To compare the perioperative ( intraoperative and postoperative) blood loss and the need for autologous and homologous blood replacement in two groups of essentially identical patients undergoing a posterior spinal fusion for idiopathic scoliosis. Summary of Background Data. Reducing perioperative blood loss and the need for transfusion in patients undergoing spinal surgery is important to orthopedic surgeons. Recently, there has been interest in pharmacologic agents, particularly Amicar and Aprotinin, to assist in decreasing perioperative blood loss. In 2001, in a preliminary study, we demonstrated that Amicar appeared to be effective in reducing perioperative blood loss in patients with idiopathic scoliosis undergoing a posterior spinal fusion and segmental spinal instrumentation. This was a study of 28 consecutive patients receiving Amicar compared to a historical control group of the 31 previous consecutive patients with the same study criteria. The current study was performed to confirm our preliminary findings. Methods. We analyzed the perioperative blood loss of 36 patients with idiopathic scoliosis who were blindly randomized by the operating room pharmacy into an Amicar and control group. The criteria to be included in the study was the same as the preliminary study: diagnosis of idiopathic scoliosis, age at surgery 11 to 18 years, posterior spinal fusion and segmental spinal instrumentation only, autogenous iliac crest bone graft or homologous cancellous bone graft, and a signed agreement to participate in the study. The patients in both groups had the same anesthetic technique, intraoperative procedure, instrumentation, postoperative management, and standardized indications for transfusions. Results. Before surgery, the patients in both groups were essentially identical. The distribution of patients and their results was not known until the completion of the study. Patients in the Amicar group demonstrated a statistically significant decrease in perioperative blood loss and the need for autologous blood transfusion. Interestingly, this decrease was predominantly in the postoperative suction drainage. This may be due to elevated fibrinogen levels induced by Amicar. The patients taking Amicar had no intraoperative or postoperative thromboembolic complications. Conclusions. The results of this study confirmed that the use of intraoperative Amicar is a safe, effective, and inexpensive method to significantly reduce perioperative blood loss in patients with idiopathic scoliosis undergoing posterior spinal fusion and segmental spinal instrumentation. The results have allowed us to reduce our recommendation for perioperative autologous blood donation, thereby further decreasing costs.