Intravenous and Oral Tranexamic Acid Are Equivalent at Reducing Blood Loss in Thoracolumbar Spinal Fusion

A Prospective Randomized Trial

Charles C. Yu, MD; Omar Kadri, MD; Allen Kadado, MD; Morenikeji Buraimoh, MD; Jacob Pawloski, BS; Stephen Bartol, MD; Gregory Graziano, MD

Disclosures

Spine. 2019;44(11):755-761. 

In This Article

Abstract and Introduction

Abstract

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 intravenous (IV) versus oral (PO) tranexamic acid (TXA).

Summary of Background Data: The use of antifibrinolytic agents such as TXA to decrease operative blood loss and allogenic blood transfusions is well documented in the literature. While evidence supports the use of IV and topical formulations of TXA in spine surgery, the use of PO TXA has not been studied.

Methods: Eighty-three 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 three 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: Fourty three patients received IV TXA and 40 patients received PO TXA. Patient demographic factors were similar between groups except for body mass index (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 with 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 deep venous thrombosis/pulmonary embolism (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

Introduction

Elective thoracolumbar spinal fusion surgery is associated with significant perioperative blood loss frequently requiring allogeneic blood transfusions, thereby increasing the risks of infection, blood incompatibility, and allergic reactions. Historically, several methods of blood conservation have been utilized, such as autologous blood predonation, antifibrinolytic drugs, and red blood cell salvage.[1] Tranexamic acid (TXA) is a synthetic amino acid derivative that prevents the activation of plasminogen, stabilizing fibrin clots.[2] Clinically, TXA has been shown to reduce perioperative blood loss, as well as the risk of blood transfusion after spinal fusions.[3,4] As a result, the use of TXA in spinal fusion surgeries has been increasing in popularity.[5–7]

TXA can be given intravenously (IV), topically, and orally (PO). Much of the orthopedic literature focuses on the IV formation. There is evidence supporting the use of PO TXA in the gynecologic and recently the adult reconstruction literature.[8] Although IV TXA is effective in reducing blood loss,[9] it is a costly medication, ranging from $47 to $108 depending on formulation.[10] To our knowledge, there is no prospective study comparing perioperative blood loss in patients undergoing elective thoracolumbar spine surgery treated with IV versus PO TXA. Potential advantages of the oral formulation include lower medication cost and ease of administration.

Therefore, the objective of this prospective randomized study was to compare the efficacy of IV and PO routes of TXA on perioperative blood loss and allogeneic blood transfusion rate in adult patients undergoing posterior thoracolumbar instrumented fusion surgery.

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