Use of aspirin for the prevention of lower extremity deep venous thrombosis

Whereas aspirin is recommended and widely used to prevent arterial thrombosis, its role in the prevention of deep venous thrombosis is not well defined. Aspirin is well accepted, easy to manage with few risks and low cost, and thus ideal for thromboprophylaxis if evidence shows it is effective. Recent guidelines and large studies were reviewed. Recent guidelines include aspirin as an acceptable thromboprophylactic agent after hip and knee orthopedic surgery despite continued publication of underpowered and contradictory studies. Two large randomized controlled trials pooled together suggest that low-dose (100 mg) aspirin is a reasonable alternative to prevent recurrence of venous thromboembolism (VTE) in patients who have been treated for a first episode of unprovoked VTE. We suggest that the current practice using aspirin to prevent thromboembolism include cautious discussion of the benefits and risks of this agent before use in a patient until precise clarification of dosage and treatment length is available. Despite inclusion of aspirin in the guidelines for orthopedic surgery, there is little evidence to support its use for primary prevention of VTE. Until definitive unbiased trials are published, we suggest that aspirin remain a realistic option to use for secondary prevention of VTE, especially compared with the option of using no prophylaxis.