title: Computerized venous strain-gauge plethysmography is a reliable method for measuring venous function.
abstract: OBJECTIVE
  To achieve reference values for computerized strain-gauge plethysmography (SGP), to assess reproducibility, and to evaluate the influence of different factors such as age, gender, body mass index, and symptomatic post-thrombotic disease on commonly used variables.
  
  
  METHODS
  Sixty-three healthy controls and 56 patients with previous deep venous thrombosis (DVT) were included. All participants underwent computerized SGP with evaluation of outflow capacity, as well as evaluation of venous reflux and muscle pump function.
  
  
  RESULTS
  All variables were significantly reduced in DVT limbs, both compared with contralateral limbs and with healthy controls. Only two patients had all values within normal ranges (=mean ± 2 SD in controls). Measures of outflow capacity had a coefficient of variation (CV) of 5-6% and exercise-induced volume changes a CV of 10-15%. In symptomatic post-thrombotic limbs half-refilling time was significantly related to presence of edema (R = -0.28, p < .05) and to chronic skin changes (R = -0.58, p < .001).
  
  
  CONCLUSIONS
  We suggest that our values in healthy controls can be used as new reference values for computerized venous strain-gauge plethysmography. The computerized design ensures high reproducibility and the results indicate that this is a very useful and sensitive test for functional quantitative assessment of patients with venous disease.
authors.affiliation: Department of Clinical Physiology, Södersjukhuset, Stockholm, Sweden; Karolinska Institutet, Stockholm, Sweden. Electronic address: stefan.rosfors@sodersjukhuset.se.
authors.forename: S
authors.initials: S
authors.lastname: Rosfors
authors.affiliation: Department of Clinical Physiology, Södersjukhuset, Stockholm, Sweden; Karolinska Institutet, Stockholm, Sweden.
authors.forename: L M
authors.initials: LM
authors.lastname: Persson
authors.affiliation: Karolinska Institutet, Stockholm, Sweden; Department of Vascular Surgery, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: L
authors.initials: L
authors.lastname: Blomgren
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D057205:Automation, Laboratory; D001783:Blood Flow Velocity; D015992:Body Mass Index; D002138:Calibration; D016022:Case-Control Studies; D005260:Female; D006439:Hemodynamics; D006801:Humans; D016014:Linear Models; D035002:Lower Extremity / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D010991:Plethysmography / Q000379:methods* / Q000592:standards; D011237:Predictive Value of Tests; D012016:Reference Values; D012039:Regional Blood Flow; D015203:Reproducibility of Results; D012737:Sex Factors; D014680:Veins / Q000503:physiopathology; D020246:Venous Thrombosis / Q000175:diagnosis* / Q000503:physiopathology; D055815:Young Adult
keywords: Chronic venous disease; Post-thrombotic disease; Reference values; Venous function; Venous plethysmography