title: Validation of the Villalta scale in assessing post-thrombotic syndrome using clinical, duplex, and hemodynamic comparators.
abstract: BACKGROUND
  The Villalta scale (VS) was developed by Prandoni and introduced as an abstract in 1994 as a disease-specific assessment questionnaire to diagnose and classify the severity of post-thrombotic syndrome (PTS). While validation using quality-of-life assessments and reproducibility have been reported as good, limited data exist as how the VS compares against generalized assessment tests in defining the severity of PTS. The aim of this study was to compare the VS against the Venous Clinical Severity Score (VCSS), the C of the CEAP classification, the Venous Segmental Disease Score (VSDS), and the Venous Filling Index (VFI) of air plethysmography.
  
  
  METHODS
  Baseline data generated from a recent single-center prospective clinical trial comparing graduated elastic compression stocking performance on 40 legs in 34 patients with PTS were analyzed. Ancillary data from this study were used to assess the measurement properties of the VS. All the legs had PTS defined as persisting leg symptoms/signs at least 6 months after a deep vein thrombosis with evidence of deep venous obstruction and/or deep venous reflux on duplex ultrasound. Unadjusted VS scores were used so patients with ulceration with a VS <15 were not automatically upgraded to a score of 15.
  
  
  RESULTS
  The number of legs by the C part of the CEAP classification was: C0 = 2, C2 = 1, C3 = 3, C4a = 12, C4b = 7, C5 = 12, and C6 = 3. The median (interquartile range) of age, VS, VCSS, VSDS, and VFI were 62 years (52-73 years), 10 (5-14), 8 (5-10), 5 (4-6.5), and 4.9 (2.8-7.9) mL/s, respectively. The VS had a highly significant and moderate-to-good correlation (Spearman) with the VCSS (r = .609; P < .0005) and the C of CEAP (r = .556, P < .0005). When the VFI was used as a hemodynamic benchmark, the VS correlation outperformed the other assessment tests (r = .499; P = .001). However, the VCSS correlation with the VFI was also significant (r = .480; P = .002). Surprisingly, the VSDS did not correlate with any assessment tests. No correlation could be detected within the VS between patient symptoms and their clinical signs. Correlations between the VS and the VCSS (r = .775) and C class (r = .779) improved when the VS patient-reported part was excluded.
  
  
  CONCLUSIONS
  These results indicate that the VCSS and the C of CEAP may also be useful in the assessment of PTS severity, and the VFI may provide a clinically meaningful hemodynamic evaluation. However, using the VFI as a reference, there was no essential difference between the VS and the VCSS.
authors.affiliation: Josef Pflug Vascular Laboratory, Ealing Hospital, Middlesex, United Kingdom; Department of Vascular Surgery, Imperial College, London, United Kingdom; Department of Vascular Surgery, Northwick Park Hospital, Middlesex, United Kingdom. Electronic address: c.lattimer09@imperial.ac.uk.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Lattimer
authors.affiliation: Josef Pflug Vascular Laboratory, Ealing Hospital, Middlesex, United Kingdom; Department of Vascular Surgery, Imperial College, London, United Kingdom.
authors.forename: Evi
authors.initials: E
authors.lastname: Kalodiki
authors.affiliation: Josef Pflug Vascular Laboratory, Ealing Hospital, Middlesex, United Kingdom.
authors.forename: Mustapha
authors.initials: M
authors.lastname: Azzam
authors.affiliation: Josef Pflug Vascular Laboratory, Ealing Hospital, Middlesex, United Kingdom; Department of Vascular Surgery, Imperial College, London, United Kingdom; Department of Vascular Surgery, Northwick Park Hospital, Middlesex, United Kingdom.
authors.forename: George
authors.initials: G
authors.lastname: Geroulakos