Spine (Phila Pa 1976). 2018 Dec 11;Epub ahead of print

# Intravenous and Oral Tranexamic Acid are Equivalent at Reducing Blood Loss in Thoracolumbar Spinal Fusion: A Prospective Randomized Trial.

Yu C, Kadri O, Kadado A, Buraimoh M, Pawloski J, Bartol S, Graziano G

STUDY DESIGN: A prospective randomized trial of patients enrolled at a university affiliated tertiary medical center between February and December 2017.

OBJECTIVE: To compare perioperative blood loss in patients undergoing elective posterior thoracolumbar fusion who were treated with IV versus PO TXA.

SUMMARY OF BACKGROUND DATA: The use of antifibrinolytic agents such as tranexamic acid (TXA) to decrease operative blood loss and allogenic blood transfusions is well documented in the literature. While evidence supports the use of intravenous (IV) and topical formulations of TXA in spine surgery, the use of oral (PO) TXA has not been studied.

METHODS: 83 patients undergoing thoracolumbar fusion were randomized to receive 1.95 g of PO TXA 2 hours preoperatively or 2 g IV TXA (1 g before incision and 1 g before wound closure) intraoperatively. The sample was further stratified into 3 categories based on number of levels fused (1-2 level fusions, 3-5, and >5). The primary outcome was the reduction of hemoglobin. Secondary outcomes included calculated blood loss, drain output, postoperative transfusion, complications, and length of hospital stay. Equivalence analysis was performed with a two one-sided test (TOST). A P-value of <0.05 suggested equivalence between treatments.

RESULTS: 43 patients received IV TXA and 40 patients received PO TXA. Patient demographic factors were similar between groups except for BMI. The mean reduction of hemoglobin was similar between IV and PO groups (3.36 g/dL vs. 3.43 g/dL, respectively; P = 0.01, equivalence). Similarly, the calculated blood loss was equivalent (1235 mL vs. 1312 mL, respectively; P = 0.02, equivalence). Eight patients (19%) in IV TXA group received a transfusion compared to five patients in PO TXA group (13%) (P = 0.44). One patient (2% and 3% in IV and PO, respectively) in each group experienced a DVT/PE (P = 0.96).

CONCLUSION: Patients treated with IV and PO TXA experienced the same perioperative blood loss after spinal fusions. Given its lower cost, PO TXA represents an excellent alternative to IV TXA in patients undergoing elective posterior thoracolumbar fusion and may improve healthcare cost-efficiency in the studied population.

LEVEL OF EVIDENCE: 1