title: Comparison of new continuous measurements of ambulatory venous pressure (AVP) with conventional tiptoe exercise ambulatory AVP in relation to the CEAP clinical classification of chronic venous disease.
abstract: BACKGROUND
  Quantitative measurements of chronic venous insufficiency (CVI) are sensitive in detecting the presence of CVI but have low specificity in differentiating clinical severities of CVI as defined by the CEAP classification. One possible reason for this is measurement techniques do not assess variables that reflect hemodynamic changes that occur during normal exercise. Our aim was to compare the association of variables determined from a new technique, continuous ambulatory venous pressure monitoring (CAVPM), and those of conventional AVP measurement with the clinical severity of chronic venous insufficiency in patients with primary venous reflux.
  
  
  METHODS
  Fifty-four limbs of 49 patients with CVI and 15 healthy controls were studied. CVI clinical severity was classified according to CEAP as C2&C3 (mild disease), C4 (moderate disease), and C5&C6 (severe disease). All participants underwent duplex ultrasound scanning to rule out the presence of reflux in the control group and to confirm it in the patient groups. Conventional AVP measurements, including 90% refilling time (RT90), were compared with the new CAVP variables of mean walking pressure (MWP) and percentage fall in walking pressure (%FWP). Data were analyzed by analysis of variance using the Kruskal-Wallis test, and comparisons between groups were performed using Mann-Whitney tests. Discriminant analysis was used to determine the ability of a test to classify limbs into clinical classes.
  
  
  RESULTS
  Conventional AVP measurements could not differentiate between the control group and the presence of mild disease (P = .56) but did differentiate between controls and severe disease as well as mild and severe disease (P < .001). RT90 detected differences between controls and reflux groups (P < .001) but not between moderate (C4) and severe (C5&C6) clinical groups (P > .5). MWP and %FWP showed significant differences between all clinical severities and controls (P < .001).
  
  
  CONCLUSIONS
  In the assessment of CVI, mean walking pressure and percent fall in walking pressure are more reliably associated with anatomic distribution of reflux and clinical severity of CVI than the gold standard investigations of conventional AVP and RT90.
authors.affiliation: Department of Vascular Surgery at Queen Elizabeth Hospital, UK. roneifell@hotmail.com
authors.forename: Ron K G
authors.initials: RK
authors.lastname: Eifell
authors.forename: Hamdy Y
authors.initials: HY
authors.lastname: Ashour
authors.forename: Tim A
authors.initials: TA
authors.lastname: Lees
mesh_terms: D000328:Adult; D000368:Aged; D018660:Blood Pressure Monitoring, Ambulatory / Q000295:instrumentation*; D002908:Chronic Disease; D004867:Equipment Design; D005080:Exercise Test; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012501:Saphenous Vein / Q000503:physiopathology*; D012720:Severity of Illness Index; D014034:Toes; D014689:Venous Insufficiency / Q000145:classification* / Q000503:physiopathology*; D014690:Venous Pressure / Q000502:physiology