title: Ultrasound screening for asymptomatic deep vein thrombosis after major orthopaedic surgery: the VENUS study.
abstract: BACKGROUND
  Venography is currently used to assess the incidence of deep vein thrombosis (DVT) in dose-finding and confirmatory trials of new antithrombotic agents. Centrally adjudicated, complete compression ultrasound (CCUS) could be a non-invasive alternative to venography.
  
  
  OBJECTIVE
  A substudy of two, similarly designed, phase IIb trials of a novel, oral anticoagulant for the prevention of venous thromboembolism after elective hip or knee arthroplasty was undertaken to validate CCUS against venography.
  
  
  METHODS
  Patients received study drugs until mandatory, bilateral venography was performed 7 +/- 2 days after surgery. CCUS was performed within 24 h after venography by sonographers blinded to the venography result. Sonographers were trained and certified for the standardized examination and documentation procedure. Venograms and sonograms were adjudicated centrally at different sites by two independent readers; discrepancies between readers were resolved by consensus.
  
  
  RESULTS
  A total of 1104 matching pairs of evaluable venograms and sonograms were obtained from the participants of the two trials (n = 1435): 19% of venograms and 20% of sonograms were not evaluable. The observed frequency of any DVT was 18.9% with venography and 11.5% with CCUS. Sensitivity of CCUS compared with venography was 31.1% for any DVT (95% confidence interval 23.4, 38.9), 21.0% (2.7, 39.4) for proximal DVT, and 30.8% (23.1, 38.6) for distal DVT. The figures for specificity were 93.0% (91.0, 95.1), 98.7% (98.0, 99.5), and 93.3% (91.5, 95.3), respectively.
  
  
  CONCLUSIONS
  Based on these results, centrally adjudicated CCUS will be unable to replace venography for DVT screening early after major orthopaedic surgery in studies evaluating anticoagulant drugs.
authors.affiliation: Division of Angiology, University Hospital Carl Gustav Carus, Dresden, Germany. sebastian.schellong@uniklinikum-dresden.de
authors.forename: S M
authors.initials: SM
authors.lastname: Schellong
authors.forename: J
authors.initials: J
authors.lastname: Beyer
authors.forename: A K
authors.initials: AK
authors.lastname: Kakkar
authors.forename: K
authors.initials: K
authors.lastname: Halbritter
authors.forename: B I
authors.initials: BI
authors.lastname: Eriksson
authors.forename: A G G
authors.initials: AG
authors.lastname: Turpie
authors.forename: F
authors.initials: F
authors.lastname: Misselwitz
authors.forename: P
authors.initials: P
authors.lastname: Kälebo
mesh_terms: D000925:Anticoagulants / Q000009:adverse effects; D017984:Enoxaparin / Q000008:administration & dosage; D006622:Hip Prosthesis / Q000009:adverse effects; D006801:Humans; D007720:Knee Prosthesis / Q000009:adverse effects; D009025:Morpholines / Q000008:administration & dosage; D019637:Orthopedic Procedures / Q000009:adverse effects*; D010690:Phlebography / Q000706:statistics & numerical data; D011183:Postoperative Complications / Q000000981:diagnostic imaging* / Q000209:etiology* / Q000517:prevention & control; D000069552:Rivaroxaban; D012680:Sensitivity and Specificity; D013876:Thiophenes / Q000008:administration & dosage; D014463:Ultrasonography / Q000379:methods / Q000706:statistics & numerical data; D020246:Venous Thrombosis / Q000000981:diagnostic imaging* / Q000209:etiology* / Q000517:prevention & control
chemical_list: D000925:Anticoagulants; D017984:Enoxaparin; D009025:Morpholines; D013876:Thiophenes; D000069552:Rivaroxaban