Are antithrombotic agents necessary for head and neck microvascular surgery?

The aim of this prospective study was to determine the effect of antithrombotic agents in preventing thrombosis after head and neck reconstructive surgery. A randomized clinical trial of referred patients undergoing free flap surgery between February 2015 and July 2017 was conducted. Four hundred and fifty-four patients were randomly assigned to group A (n=153), administered aspirin and low molecular weight dextran; group B (n=150), administered low molecular weight heparin; and group C (n=151), not administered any antithrombotic agent. Patient demographic characteristics, donor site, thrombosis, haematoma, and flap failure were recorded. Coagulation values including platelet count, prothrombin time, and activated partial thromboplastin time were measured during the perioperative period. Repeated-measures ANOVA and the χ test were used for data comparisons. No significant inter-group differences were observed for postoperative microvascular thrombosis (P=0.536) or flap failure (P=0.615) among the three groups. There were more postoperative haematoma revisions in group B than in groups A and C (P=0.032). It is concluded that postoperative antithrombotic agents neither provide a significant improvement in the free flap success rate nor decrease the risk of thrombosis and may increase the risk of haematoma.