Effectiveness of prophylactic tranexamic acid versus placebo or no intervention for reducing blood loss in healthy patients undergoing orthognathic surgery: a systematic review protocol.

[OBJECTIVE] The objective of this review is to evaluate the effectiveness of perioperative prophylactic tranexamic acid for reducing blood loss in orthognathic surgery in healthy patients.

[INTRODUCTION] Orthognathic surgery can cause significant hemorrhage, which requires postoperative blood transfusions. The most widely studied pharmaceutical adjunct for reducing blood loss is tranexamic acid, a synthetic amino acid that reversibly inhibits plasminogen activation. It is widely used and validated in other surgical procedures to limit blood loss; however, it is not a gold standard in orthognathic surgery.

[INCLUSION CRITERIA] We will include clinical trials comparing tranexamic acid to appropriate controls. The primary outcomes are intraoperative blood loss, change in hematocrit/hemoglobin level, and need for blood transfusion. Secondary outcomes include operating time, length of hospital stay, and adverse reactions. Studies of patients with pre-existing coagulopathies and those undergoing only minor orthognathic surgery (eg, genioplasty) will be excluded.

[METHODS] We will search 3 electronic databases (PubMed, Embase, and Cochrane Library) from database inception. Titles, abstracts, and full-text papers will be assessed against the inclusion criteria by 2 independent reviewers. Risk of bias will be assessed using the Cochrane Risk of Bias 2.0 tool. Data will be extracted by 2 independent reviewers. Meta-analysis will be conducted for all outcomes where appropriate, with weighted mean differences used for intraoperative blood loss, changes in hematocrit/hemoglobin levels, operation time, and length of stay; and risk ratio for transfusion rates and adverse outcomes. Certainty of the evidence will be presented using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach.

[SYSTEMATIC REVIEW REGISTRATION NUMBER] PROSPERO CRD42022314403.