Tranexamic Acid: Is It As Safe As We Think?

Goals/Purpose: TXA is widely used by surgeons for its hemostatic properties and has been shown to not increase the risk of deep venous thrombosis. However, there are little to no data regarding the effect of TXA at the microvascular level, particularly how it affects skin flap perfusion. This knowledge gap is of particular concern for surgeons who perform procedures that include elevation of random flaps, for both reconstructive and aesthetic applications, where thin skin flaps rely on random pattern blood flow. We hypothesize that the use of TXA in skin flap surgeries does not negatively affect skin flap perfusion.

Methods/Technique: A dorsal McFarlane flap model (3 cm x 9 cm) with a cranial pedicle was performed in 22, 250-300g Sprague Dawley rats receiving either 1) IV TXA at a therapeutic in vivo dose (10 mg/kg), 2) IV PBS of equal volume, 3) subcutaneous (injected into the flap) TXA at therapeutic in vivo dose (10 mg/kg), or 4) subcutaneous (injected into the flap) PBS injections of equal volume. The TXA or PBS was injected intravenously via tail vein as a 1 mL bolus or subcutaneously into the flap in 20, 100 microliter injections 5 minutes prior to incision. Area percent gross necrosis of the flap was measured using image analysis software at days 7 and 14. In vivo fluorescent imaging following intraperitoneal fluorescein injection was also performed at each timepoint to assess flap perfusion and congruence with gross imaging. One-way ANOVA was performed to assess differences in area percent gross necrosis between groups.

Results/Complications: There was no difference between groups for area percent gross necrosis at days 7 (p= 0.2521) and 14 (p= 0.0993) but there was a suggestive trend towards lower necrosis in both TXA receiving groups. This was supported by fluorescent imaging findings.

Conclusion: Perioperative administration of systemic or local TXA does not compromise the perfusion of random-pattern skin flaps and may, in fact, provide benefits. Our preliminary findings support the continued use of TXA in procedures involving large flap elevation. However, further studies are necessary to confirm these results.