title: Reflux time estimation on air-plethysmography may stratify patients with early superficial venous insufficiency.
abstract: OBJECTIVE
  It has been suggested that quantification of haemodynamic parameters of venous disease may complement clinical assessment and may help identify a group of patients with severe venous disease or alternatively patients with early venous disease. However, there has been very little work to prove this hypothesis. The venous filling index (VFI) of air-plethysmography (APG) can quantify severity and treatment effect but has limited discriminatory value. However, the components of the VFI, total venous volume (VV) and time to reach 90% of VV (VFT90), have never been fully studied. The aim was to investigate the contribution of VV and VFT90 to an elevated VFI and determine their relationship to great saphenous vein (GSV) diameter and clinical severity scoring.
  
  
  METHODS
  Ninety-three consecutive patients/legs (22-78 years) with primary GSV reflux (>0.5 seconds) awaiting endovenous treatment were recruited. CEAP (clinical, aetiological, anatomical and pathological elements) assessments were: 33 (35.5%) C₂, 14 (15.0%) C₃, 29 (31.2%) C4a, 5 (5.4%) C4b, 7 (7.5%) C₅ and 5 (5.4%) C₆. The median venous clinical severity score (VCSS) was 6 (2-20) and the averaged GSV diameter at three sites was 7.5 mm (4-12). The VFI, VV and VFT90 were recorded using APG.
  
  
  RESULTS
  There was no correlation between the VV and the VFT90 (r = -0.103, P = 0.324). The VFI, VV and VFT90 significantly correlated (P < 0.0005, Spearman) with the GSV diameter: r = 0.623, r = 0.567, r = -0.432, respectively, and the C of CEAP (P < 0.05): r = 0.4, r = 0.225, r = -0.343, respectively. None of the 25 (26.9%) patients with a VFT90 > 25 seconds were among the 17 (18.3%) patients in categories C4b-6 or with a VCSS > 9 (P = 0.005, Fisher's exact test, corrected odds ratio: 17.3).
  
  
  CONCLUSIONS
  The VFT90 complements the VFI as a marker of severe superficial venous insufficiency. However, in contrast to the VFI, it may have discriminatory value in stratifying patients with early disease into two groups based on the severity of haemodynamic impairment.
authors: Ealing Hospital & Imperial College, London SW7 2AZ, UK.
authors: C R
authors: CR
authors: Lattimer
authors: E
authors: E
authors: Kalodiki
authors: M
authors: M
authors: Azzam
authors: G
authors: G
authors: Geroulakos
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010991:Plethysmography / Q000379:methods; D014689:Venous Insufficiency / Q000473:pathology* / Q000503:physiopathology*
keywords: CEAP clinical class; air-plethysmography; reflux; venous insufficiency; venous severity score