title: Aspirin in the primary prophylaxis of venous thromboembolism in surgical patients.
abstract: BACKGROUND
  Venous thromboembolism (VTE) is a common complication in surgical patients, especially those undergoing lower limb orthopaedic procedures as well as oncological resectional surgery. Numerous studies have evaluated the role of acetylsalicylic acid (ASA, aspirin) in primary VTE prevention, with contradictory results reflected in divergent guidelines. We reviewed current evidence for ASA as primary VTE prophylaxis.
  
  
  METHODS
  English language studies meeting our inclusion criteria were retrieved from PubMed, EMBASE and Cochrane databases. Six studies (3 meta-analyses and 3 randomized trials) comparing ASA with placebo and 7 studies (1 meta-analysis, 5 randomized trials, and 1 prospective) comparing ASA with other anticoagulants were included in the final analysis. Retrospective studies and case reports were excluded.
  
  
  RESULTS
  ASA is more effective than placebo in primary VTE prevention. Although there is clinical equipoise when ASA is compared with other anticoagulants, studies specific to orthopaedic surgery suggest that ASA appears as effective as low molecular weight heparin (LMWH) and may reduce bleeding risk. Extended prophylaxis up to 4 weeks post surgery reduces VTE episodes.
  
  
  CONCLUSIONS
  ASA may be considered as a potential strategy in primary VTE prophylaxis in orthopaedic patients at high-risk of bleeding complications. Further studies comparing ASA with LMWH/oral anticoagulants in primary thromboprophylaxis following non-orthopaedic surgery are warranted.
authors.affiliation: Department of Surgery, University Hospital Limerick, Ireland. Electronic address: sahebalm@tcd.ie.
authors.forename: Shaheel M
authors.initials: SM
authors.lastname: Sahebally
authors.affiliation: Department of Surgery, University Hospital Limerick, Ireland.
authors.forename: Donagh
authors.initials: D
authors.lastname: Healy
authors.affiliation: Department of Vascular Surgery, University College Hospital Galway, Galway, Ireland.
authors.forename: Stewart R
authors.initials: SR
authors.lastname: Walsh
mesh_terms: D001241:Aspirin / Q000627:therapeutic use*; D005343:Fibrinolytic Agents / Q000627:therapeutic use; D014943:Global Health; D006801:Humans; D015994:Incidence; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D011322:Primary Prevention / Q000379:methods*; D012307:Risk Factors; D013997:Time Factors; D054556:Venous Thromboembolism / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*
chemical_list: D005343:Fibrinolytic Agents; D001241:Aspirin
keywords: Acetylsalicylic acid; Aspirin; Deep venous thrombosis; Prophylaxis; Pulmonary embolism; Venous thromboembolism