Friday, September 28, 2018 9:00 AM–10:00 AM best papers Friday: 153. Intravenous and oral tranexamic acid are equivalent at reducing blood loss in thoracolumbar spinal fusion: a prospective randomized trial

Abstract

BACKGROUND CONTEXT Due to the significant risks and complications associated with blood loss and allogeneic transfusions, identifying safe and effective ways to minimize blood loss during spine surgery is crucial. Tranexamic acid (TXA) is effective at reducing blood loss and transfusion rate in orthopaedic surgery. Although intravenous (IV) TXA has been shown to be successful in patients undergoing spine fusion, no studies in the current literature have investigated the efficacy of its low cost counterpart, oral (PO) TXA. PURPOSE The purpose of this prospective randomized trial was to determine if PO TXA is equivalent to IV TXA in reducing blood loss in spinal fusion. STUDY DESIGN/SETTING This study was a single-center, randomized, prospective trial designed to test equivalence between IV and oral TXA in the setting of thoracolumbar fusion between February and December 2017. PATIENT SAMPLE Enrolled patients were randomly assigned between the two treatment groups of IV and oral TXA using a random number algorithm. A total of 44 patients received IV TXA and 45 patients received PO TXA. OUTCOME MEASURES The primary outcome was reduction of hemoglobin. In addition, calculated blood loss, drain output, postoperative transfusion, complications, and length of hospital stay were investigated. METHODS In this prospective randomized trial, 89 patients undergoing thoracolumbar fusion were randomized to receive 1.95g of PO TXA 2hours preoperatively or 2g IV TXA (1g before incision and 1g before wound closure) intraoperatively. Because the number of fusion levels can influence blood loss, the sample was sub-categorized by the number of vertebral levels arthrodesed (1–2 levels, 3–5 levels, >5 levels). Power analysis determined that 30 patients were needed in each group. Equivalence analysis was performed with a two one-sided test (TOST). A P-value of RESULTS Patient demographic factors were similar between groups except for BMI. The mean reduction of hemoglobin was similar between IV and PO groups (3.35g/dL vs. 3.18g/dL, respectively; P=.016, equivalence). Similarly, the calculated blood loss was equivalent (1233mL vs. 1227mL, respectively; P=.027, equivalence). Eight patients (18%) in IV TXA group received a transfusion compared to six patients in PO TXA group (13%) (P=.53). One patient (2% each) in each group experienced a DVT/PE (P=.99). CONCLUSIONS Intravenous and PO TXA are both effective in reducing the expensive perioperative costs associated with blood loss and transfusions after spinal fusions. Oral TXA provides equivalent reductions in blood loss at a greatly reduced cost compared to the IV formulation. As the incidence of spinal fusions increases in the near future, adopting an oral regimen of TXA can drastically improve cost-efficiency for our health care system.