title: Pathophysiology of chronic venous insufficiency in adults with a Fontan circulation (a pre-defined substudy of the CALF investigation).
abstract: OBJECTIVE
  To investigate the pathophysiology of chronic venous insufficiency in adults with a Fontan circulation.
  
  
  BACKGROUND
  Chronic venous insufficiency (CVI) is prevalent in adults with a Fontan circulation, however the underlying pathophysiology has not been identified. We defined the prevalence of venous reflux and obstruction in a Fontan population, identified associated factors, and assessed the hypothesis that venous reflux correlates with clinical CVI in adults with a Fontan circulation.
  
  
  METHODS
  Fifty-one adult Fontan subjects from the Congenital Heart Disease in Adults: Lower Extremity Systemic Venous Health in Fontan Patients (CALF) study, ten control subjects without cardiac disease, and ten comparator subjects with repaired tetralogy of Fallot underwent lower extremity Doppler venous ultrasound. We investigated 10 venous segments in each subject for venous obstruction and reflux.
  
  
  RESULTS
  The prevalence of venous reflux was significantly greater in the Fontan population compared to healthy controls (51% vs. 10%, p=0.03). Venous flow patterns demonstrated a range of pulsatility and biphasic flow in many subjects. There was no evidence of venous obstruction in any subject. Venous reflux did not correlate with clinical venous insufficiency; 49% of Fontan subjects with observed venous reflux demonstrated no clinical signs of venous disease. Predictors of venous reflux in multivariate analysis were single right ventricle (p=0.03), use of anti-arrhythmic medications (p=0.04), and family history of venous disease (p=0.003).
  
  
  CONCLUSIONS
  Venous reflux is highly prevalent and venous obstruction is absent in adults with a Fontan circulation. Clinical CVI underestimates pathophysiologic venous insufficiency in adults with a Fontan circulation.
authors.affiliation: Children's Hospital Boston, Department of Cardiology, Boston, MA, United States. abhatt@partners.org
authors.forename: Ami B
authors.initials: AB
authors.lastname: Bhatt
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Landzberg
authors.forename: Marie
authors.initials: M
authors.lastname: Gerhard-Herman
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Rodriguez-Huertas
authors.forename: Dionne
authors.initials: D
authors.lastname: Graham
authors.forename: Anne Marie
authors.initials: AM
authors.lastname: Valente
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D018729:Fontan Procedure / Q000009:adverse effects / Q000639:trends*; D006330:Heart Defects, Congenital / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D035002:Lower Extremity / Q000098:blood supply* / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D013771:Tetralogy of Fallot / Q000503:physiopathology* / Q000601:surgery; D014689:Venous Insufficiency / Q000175:diagnosis / Q000503:physiopathology*; D055815:Young Adult