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

Discussion

Significant blood loss from spine surgery can lead to allogeneic blood transfusion and other significant complications.[15,16] Strategies have been designed to reduce perioperative blood loss in complex spine surgery, such as preoperative administration of EPO, autologous blood predonation, intraoperative cell salvage, controlled hypotension, and use of antifibrinolytic agents.[17] The antifibrinolytic medication, TXA, especially in its IV form, has been frequently used in the last few decades in pediatric scoliosis,[7,8,18,19] adult spinal deformity,[20] and degenerative spine cases.[9,21–26] Furthermore, IV TXA has been shown to be safe and effective in reducing blood loss and need for transfusion.[27] This is the first study in the spine literature that compares IV versus PO formulations of TXA. We found no difference in the efficacy between the two routes of administration in both the primary outcome of hemoglobin drop and secondary outcomes. PO TXA appears to be as safe as IV TXA in regards to postoperative thromboembolic events and infections. The safety profile of PO TXA is consistent with that of other antifibrinolytic agents reported in previous studies.[3,27]

TXA can be administered intravenously, topically, and orally. Compared with total joint arthroplasty, spine surgery traditionally has had a preference for intravenous over topical administration due to larger exposures and more extensive dissection. On the other hand, proponents of topical TXA argue that it can provide a maximum concentration at the bleeding site while minimizing systemic absorption. Liang et al[28] found that topical TXA combined with Gelfoam was effective in decreasing postoperative drain output, drain duration, and hospital stay compared with both Gelfoam alone and control groups in lumbar spine surgery. Multiple studies have reported the efficacy of IV tranexamic acid in reducing blood loss by 25% to 41% while maintaining a safety profile.[8,9] However, the efficacy of PO TXA in spinal fusion surgeries has remained largely unknown. To our knowledge, current orthopedic research comparing IV and PO TXA has been limited to total joints arthroplasty literature.[10,29] Their findings are consistent with ours in that there is no difference in TXA efficacy between the IV and PO forms.

Given the ever-changing landscape of medical reimbursement, cost effective health care practice is beneficial to patients, providers, the healthcare system, and society at large. The use of TXA in orthopedic surgery has become a routine practice because it has been shown to be safe, clinically beneficial, and cost-effective.[30] Allogeneic blood transfusions carry the risk of transfusion reactions, disease transmission, and increased hospital costs.[31–33] In primary total knee arthroplasty (TKA) and total hip arthroplasty (THA), TXA offers not only savings from transfusion costs but also all hospital costs including operating room, laboratory and pharmacy costs, totaling $879 per patient.[34–37] Given that PO TXA is cheaper and easier to administer than IV TXA, switching to PO can lead to greater cost savings. In our institution, the oral TXA dosage cost $14 compared with $53 for the generic IV formulation alone (not including the cost of pharmacy preparation). As the American population continues to age, the number of spinal fusion surgeries performed in the United States will likely continue to increase from the current annual rate of about 500,000. Consequently, transitioning to PO TXA has potential to can yield cost savings of at least 20 million dollars per year for the health care system.

Several potential limitations exist in this study. First, the study population contains heterogeneity such as varying patient diagnosis and surgical technique/approach. However, heterogeneity was minimized through sub-stratification of the number of fusion levels into three categories. Posterior approach was mostly used (100% and 98% for IV and PO, respectively), and a single surgeon performed most of the cases (93% and 85% for IV and PO, respectively). Second, blood loss calculation was based on the lowest postoperative hemoglobin value, which may be inaccurate due to hemodilution if the patient was discharged before postoperative day 5.[38] However, change in hematocrit was similar for IV and PO groups. Lastly, we did not perform individual analysis in the three subgroups (1–2 levels, 3–5 levels, >5 levels) because of lack of adequate statistical power. Despite these limitations, the validity of our results should be maintained, as the same methodology was applied to both treatment arms and length of stay was not different between the two groups.

Another potential limitation is that we did not include a placebo group and assumed that PO TXA was superior to placebo based on arthroplasty literature.[5,39] We believe that using the standard IV formulation as a control instead of a pure placebo was more clinically useful. Additionally, because perioperative bleeding during spine surgery is multifactorial and can be more significant than TKA or THA,[40] we would put patients at increased risk for blood loss if we did not give TXA. Additionally, administration of TXA in spine surgery is already emerging as the standard of care, and this study is an attempt to optimize current standards. Strengths of this study include that it was completed at a single center and by a single surgeon predominantly.

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