PURPOSE: Little is known of the systemic effects of oral and maxillofacial surgery on the hemostatic balance, including the biochemical effects of tranexamic acid (TXA), on fibrin clot lysis. The present study investigated the effects of orthognathic surgery on fibrin lysis, fibrin structure, and D-dimer and evaluated the effect of TXA on these fibrinolytic measures.
MATERIALS AND METHODS: The present double-blind, controlled, and randomized, placebo study included patients referred to the Department of Oral and Maxillofacial Surgery at the University Hospital of Southern Denmark-Esbjerg from August 2014 through September 2016. The patients were elective and had a diagnosis of maxillary or mandibular deficiency, either excessive or asymmetric. All patients underwent bimaxillary orthognathic surgery (OS) with or without maxillary segmentation or additional genioplasty. The patients were blindly randomized to treatment with TXA or placebo. The primary predictor variable was OS. The secondary predictor variable was an intravenous dose of 1 g of TXA or equivalent placebo preoperatively. Blood samples were collected before surgery and 5 hours after the initiation of surgery. The primary outcome variable was lysis of fibrin. The fibrin structure properties and D-dimer were secondary outcome measures. The Mann-Whitney U test was used for the within-group comparisons. The Wilcoxon signed rank test was used for the between-group comparisons.
RESULTS: The sample included 96 patients; 45 received placebo and 51 received TXA. Fibrin lysis decreased after OS (P < .001). The fibrinolytic shutdown decreased significantly more in the TXA group than in the placebo group (P < .001). OS altered the fibrin structure properties with comparable effects in the 2 groups. D-dimer increased postoperatively but significantly less so in the TXA group than in the control group (P < .001).
CONCLUSIONS: OS is associated with fibrinolytic shutdown and alters fibrin structure properties, driving the hemostatic balance in a prothrombotic direction. The fibrinolytic shutdown is significantly amplified by TXA.