Aspirin as thromboprophylaxis in hip and knee arthroplasty: a systematic review and meta-analysis

Background: Venous thromboembolism (VTE) comprises pulmonary embolism and deep vein thrombosis and is a complication of particular concern in lower limb arthroplasty. In recent years, aspirin has emerged as a potential alternative thromboprophylactic agent, particularly after its acceptance as a recommended agent by the American College of Chest Physicians. Aspirin is favorable due to its relative cost-effectiveness and convenience compared to novel oral anticoagulants and warfarin. However, its efficacy since its inclusion in the American College of Chest Physicians guidelines remains unclear. The present systematic review aimed to establish the efficacy of aspirin in preventing VTE in total hip and knee arthroplasty. Methods: Electronic searches were performed using 6 databases from up to June 2015, identifying all relevant studies. Data were extracted and meta-analyzed. Results: Eleven relevant studies were identified for inclusion in the present meta-analysis. The overall rate of deep vein thrombosis and pulmonary embolism in both hip and knee arthroplasty was 1.2% and 0.6%, respectively. The rate of major bleeding was 0.3%. Pooled mortality rate was 0.2%. All findings demonstrated a high and significant degree of heterogeneity. Conclusion: Aspirin, both alone and in multimodal approaches to thromboprophylaxis, confers a low rate of VTE, with a low risk of major bleeding complications. However, the evidence for its use is limited by the low quality of studies and variation in dose in dosing regimes. Future randomized controlled trials should investigate the efficacy of aspirin, as well as the ideal dosing protocol for its use in thromboprophylaxis in arthroplasty.