Rationalizing post-operative prophylactic anticoagulation in reconstructive head and neck cancer patients: a review

Microsurgical reconstructive head and neck cancer patients are at high risk of venous thromboembolism. The use of anticoagulation can reduce their risk; however, this also increases their bleeding risk. It is not clear whether the benefits of treatment outweigh the risks, and whether a specific post-operative anticoagulation regime is superior. The aim of this review is to evaluate the evidence pertaining to the risks and benefits of post-operative anticoagulation and to provide a rationale for its use in head and neck cancer patients receiving free flaps. The secondary aim was to determine the optimal post-operative anticoagulation regimen. A search was conducted in the PubMed and EMBASE databases identifying studies reporting venous thromboembolism rates in reconstructive head and neck cancer patients undergoing free flaps. These studies were reviewed for their eligibility. Outcomes measured were rates of venous thromboembolism, bleeding-related and microsurgical complications. A total of 306 studies were found from the search with another seven studies identified from citations of key articles. After assessment, nine studies were included. Venous thromboembolism rates ranged from 0.5% to 7% and the rates of bleeding-related complications ranged from 2.4% up to 29%. Anticoagulation appears to lower the risk of venous thromboembolism in this patient group, but also increases the bleeding risk. Risk stratification using the Caprini risk assessment model can help surgeons make decisions. For patients with cancer, low molecular weight heparin appears to be superior to heparin given twice daily but equal to heparin given three times daily and the bleeding risk of each medication appears similar.