Prevention of Intraoperative Bleeding and Postoperative Swelling in Orthognathic Surgery Through the Use of Tranexamic Acid

Overview

Purpose of the study: * To evaluate the effect of tranexamic acid (TXA) of intraoperative blood loss in patients subjected to bi-maxillary orthognathic surgery * To evaluate the potential effect of TXA on fibrin structure * To evaluate the potential effect of TXA of binding of plasminogen to fibrin * To evaluate the potential effect of TXA on postoperative edema formation. Hypothesis: H0: Intraoperative bleeding cannot be significantly reduced by preoperative administration of tranexamic acid H0,1: Postoperative edema cannot be significantly reduced by preoperative administration of tranexamic acid

The study population consists of patients referred to simultaneous mandibular and maxillary osteotomy at the Department of Oral and Maxillofacial Surgery, Hospital of South West Denmark in 2014. Hundred patients (50 men and 50 women) will be enrolled in the study. Reportedly, the mean intraoperative blood loss in the placebo group is expected to be 436 ml with a standard deviation of 208 ml. The difference in blood loss between the TXA-group and the placebo group to be detected is 100 ml. The dropout frequency is estimated to 10%. To fulfil these assumptions a minimum of 40 patients should be included in each group to reach a power of 0.8 and an alpha of 0.05. In order to accommodate an even gender distribution a block randomization is performed resulting in the randomization of 100 patients. The patients will be randomized to receive blindly either 10 ml tranexamic acid (100 mg/ml) (Pfizer, Ballerup, Denmark) or 10 ml saline (9mg/ml) preoperatively. Intraoperative blood loss will be determined by deducting the total volume of irrigation fluids from the volume of the contents of the surgical suction device. Postoperative edema formation will be determined by 3D surface scanning and volumetric analysis will be carried out in the "Landmarker" software.