The Efficacy of Postoperative Antithrombotics in Free Flap Surgery: A Systematic Review and Meta-Analysis

Background: Although the efficacy of postoperative antithrombotics in free flap survival is well demonstrated through animal studies, debate remains in the clinical literature. This review estimates the benefits and risks of each antithrombotic drug and evaluates whether antithrombotics can produce better outcomes than nonantithrombotic treatment. Methods: English-language articles evaluating the efficacy of antithrombotics in free flap surgery through comparisons with control groups were analyzed. The outcome measures were total flap failure, pedicle thrombosis, and hematoma formation. Results: Twelve articles representing 4984 cases were analyzed. None of the antithrombotics showed significant benefits for flap survival. Heparin reduced the risk of flap loss by 35 percent, but the difference was not significant (relative risk, 0.65; 95 percent CI, 0.25 to 1.69). Dextran and aspirin showed little protective effects on pedicle thrombosis and flap failure. All antithrombotics showed increased risks of hematoma, and aspirin raised the risk of hematoma significantly (relative risk, 1.91; 95 percent CI, 1.05 to 3.47). In an analysis combining six studies comparing outcomes between the antithrombotic group and the nonantithrombotic group, antithrombotic administration did not reduce the risk of total flap loss (relative risk, 0.99; 95 percent CI, 0.72 to 1.35) or thrombosis (relative risk, 1.00; 95 percent CI, 0.74 to 1.36) but significantly increased the risk of hematoma (relative risk, 1.78; 95 percent CI, 1.20 to 2.63). Conclusions: There is little evidence suggesting that the use of antithrombotics reduces the risk of thrombosis and total flap failure. Although randomized controlled studies would be required, the risks of routine administration of antithrombotics may outweigh the benefits.