Effect of postoperative aspirin on outcomes in microvascular free tissue transfer surgery

Objective. Examine if outcomes and complication rates for free flaps vary when postoperative aspirin is used as pharmacologic thromboprophylaxis compared with no anticoagulation. Study Design. Case series with chart review. Setting. Oregon Health and Science University, an academic medical center. Subjects and Methods. A case series with chart review was performed using a prospectively maintained microvascular reconstructive database to identify cases of free tissue transfer between February 2006 and April 2010. Outcome variables included complications, flap failure, reexploration, and salvage. Chi-square analysis was performed to identify differences based on type of postoperative antithrombotic therapy. Results. A total of 390 consecutive free tissue transfer procedures were performed; 184 received no postoperative thromboprophylaxis, 142 received aspirin, 48 received low molecular weight heparin or a combination of agents, and 16 received a heparin drip. The overall complication rate was 38%, with significantly more complications in the aspirin group compared with no prophylaxis (P = .002). There was no significant difference in bleeding complications (P = .192) or flap failure (P = .839) between aspirin and no anticoagulation. There were more postoperative revisions in the aspirin group (P = .039). Conclusion. Postoperative thromboprophylaxis with aspirin after microvascular free tissue transfer does not provide an improvement in free flap survival and may be associated with a higher complication rate. Prospective, randomized studies are required to elucidate the role of postoperative pharmacotherapy for prophylaxis against microvascular thrombosis.