title: The development of postthrombotic syndrome in relationship to venous reflux and calf muscle pump dysfunction at 2 years after the onset of deep venous thrombosis.
abstract: OBJECTIVE
  Postthrombotic syndrome (PTS) develops in 40% to 60% of patients with deep venous thrombosis. Factors that are important in the development of PTS include venous reflux, deep vein obstruction, and calf muscle pump dysfunction (CMD).
  
  
  METHODS
  Reflux and CMD in relationship to the severity of PTS were evaluated in a 2-year follow-up study of patients with acute deep venous thrombosis. Duplex scanning was used to measure reflux. The supine venous pump function test (SVPT) measures CMD with strain-gauge plethysmography. The base-line examination was performed within 1 to 5 days after diagnosis. The next examinations were scheduled at 3, 6, 12, and 24 months.
  
  
  RESULTS
  The study included 86 legs, and the 2-year follow-up period was completed for 70 legs. Significantly more reflux was found in previously thrombosed vein segments, with an odds ratio of 1.8 after 3 months, of 2.1 after 6 months, of 2.5 after 12 months, and of 3.2 after 24 months. Multiple regression results showed that the most important risk factor for early clinical signs of PTS was superficial reflux in months 3, 6, and 12 (P < or =.02). Deep reflux did not have a synergistic relationship with superficial reflux in correlation with the clinical signs of PTS. The SVPT was not able to predict the development of PTS.
  
  
  CONCLUSIONS
  More reflux develops in previously thrombosed vein segments. As early as after the third month, patients with superficial reflux have an increased risk of development of the first clinical signs of PTS. Within 2 years, the SVPT shows no relationship with clinical signs of PTS.
authors.affiliation: Clinical Vascular Laboratory 810, University Hospital Nijmegen, PO Box 9101, 6500 HB Nijmegen, the Netherlands. R.vanOorschot@vasclab.azn.nl
authors.forename: José H
authors.initials: JH
authors.lastname: Haenen
authors.forename: Mirian C H
authors.initials: MC
authors.lastname: Janssen
authors.forename: Hub
authors.initials: H
authors.lastname: Wollersheim
authors.forename: Martin A
authors.initials: MA
authors.lastname: Van't Hof
authors.forename: M J M
authors.initials: MJ
authors.lastname: de Rooij
authors.forename: Herman
authors.initials: H
authors.lastname: van Langen
authors.forename: Stefan H
authors.initials: SH
authors.lastname: Skotnicki
authors.forename: Theo
authors.initials: T
authors.lastname: Thien
mesh_terms: D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007866:Leg / Q000098:blood supply; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology; D011186:Postphlebitic Syndrome / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D012044:Regression Analysis; D012307:Risk Factors; D013997:Time Factors; D018616:Ultrasonography, Doppler, Duplex; D020246:Venous Thrombosis / Q000150:complications* / Q000503:physiopathology