title: Extended lower limb venous ultrasound for the diagnosis of proximal and distal vein thrombosis in asymptomatic patients after total hip replacement.
abstract: OBJECTIVE
  To assess the performance of extended lower limb venous ultrasound (US) for the diagnosis of asymptomatic deep vein thrombosis (DVT) and to estimate a 3-month DVT incidence on repeated US after total hip replacement.
  
  
  METHODS
  Diagnostic performance study and prospective cohort study.
  
  
  METHODS
  US was compared to phlebography in 70 consecutive patients and interobserver agreement was assessed in the last 48 patients at day 8. US was repeated in these 48 patients at day 13 and day 90.
  
  
  RESULTS
  Phlebography demonstrated a DVT in 18/70 (26%) patients, with five proximal and 13 distal and US in 23/70 (33%) patients, with eight proximal and 15 distal. Sensitivity and specificity of US with 95% CI were 94% (73-100) and 89% (76-96), respectively. Sensitivity in isolated distal vein thrombosis was 92% (67-99). The Kappa coefficient for agreement between observers was 0.84 (0.66-1.00). Follow-up showed a DVT in 15/48 (31%) patients on day 8, in 20/48 patients (42%) on day 13. DVT recurred in two patients during follow-up.
  
  
  CONCLUSIONS
  The incidence of asymptomatic DVT is still significant despite prophylaxis but most DVTs remain distal and occur in the first 2 weeks. Extended US could replace phlebography for systematic screening in clinical trials using surrogate endpoints in view of its high accuracy and reliability.
authors.affiliation: Department of Vascular Medicine, Rangueil University Hospital Centre, Toulouse, France.
authors.forename: A
authors.initials: A
authors.lastname: Elias
authors.forename: A
authors.initials: A
authors.lastname: Cadène
authors.forename: M
authors.initials: M
authors.lastname: Elias
authors.forename: J
authors.initials: J
authors.lastname: Puget
authors.forename: J L
authors.initials: JL
authors.lastname: Tricoire
authors.forename: C
authors.initials: C
authors.lastname: Colin
authors.forename: D
authors.initials: D
authors.lastname: Lefebvre
authors.forename: H
authors.initials: H
authors.lastname: Rousseau
authors.forename: F
authors.initials: F
authors.lastname: Joffre
mesh_terms: D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D006801:Humans; D007866:Leg / Q000098:blood supply* / Q000000981:diagnostic imaging; D010690:Phlebography; D015203:Reproducibility of Results; D014463:Ultrasonography; D020246:Venous Thrombosis / Q000000981:diagnostic imaging* / Q000209:etiology