title: Incidence of and risk factors for iliocaval venous obstruction in patients with active or healed venous leg ulcers.
abstract: BACKGROUND
  Iliocaval venous obstruction (ICVO) can be a significant contributor to venous hypertension in patients with advanced disease. The incidence of ICVO in patients with CEAP clinical class 5 and 6 disease has not been reported. In this study, we reviewed a series of patients with healed or active venous leg ulcers to determine the incidence of ICVO and the risk factors related to its occurrence.
  
  
  METHODS
  Patients with CEAP clinical class 5 and 6 venous insufficiency underwent evaluation with duplex ultrasound scan to identify the presence of venous reflux in the deep and superficial systems and either computed tomography (CT) or magnetic resonance (MR) venography to identify ICVO. The venograms were evaluated by two separate examiners to calculate the percentage of obstruction in the iliocaval outflow tract. Demographics and risk factors related to venous disease were collected and examined for their association with severe ICVO.
  
  
  RESULTS
  A total of 78 CEAP clinical class 5 and 6 patients evaluated with either a CT or MR venogram were retrospectively reviewed. The average patient age was 59.3 years and 53.4% were men. The ulcer affected the left lower extremity in 46% of cases and 50% of patients reported a medical history of deep vein thrombosis (DVT). Overall, 37% of imaging studies demonstrated ICVO of at least 50% and 23% had obstruction of >80%. Risk factors that were found to be independently associated with a significantly higher incidence of >80% ICVO included female gender (P = .023), a medical history of DVT (P = .035), and reflux in the deep venous system (P = .035). No limb with superficial venous reflux (SVR) alone was found to have ICVO >80%.
  
  
  CONCLUSIONS
  ICVO is a frequent and underappreciated contributor to venous hypertension in patients with venous leg ulcers. Women and patients with a history of DVT or duplex scan-diagnosed deep venous reflux (DVR) have a higher incidence of outflow obstruction and should be routinely studied with CT or MR venography to allow correction in this high-risk group of patients.
authors.affiliation: University of North Carolina, Division of Vascular Surgery, 3024 Burnett-Womack, Chapel Hill, NC 27599, USA. william_marston@med.unc.edu
authors.forename: William
authors.initials: W
authors.lastname: Marston
authors.forename: Daniel
authors.initials: D
authors.lastname: Fish
authors.forename: Joshua
authors.initials: J
authors.lastname: Unger
authors.forename: Blair
authors.initials: B
authors.lastname: Keagy
mesh_terms: D000368:Aged; D003251:Constriction, Pathologic; D005260:Female; D006801:Humans; D007084:Iliac Vein / Q000000981:diagnostic imaging / Q000473:pathology; D015994:Incidence; D007871:Leg Ulcer / Q000453:epidemiology* / Q000473:pathology; D016015:Logistic Models; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D009657:North Carolina; D016017:Odds Ratio; D010690:Phlebography / Q000379:methods; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012737:Sex Factors; D014057:Tomography, X-Ray Computed; D018616:Ultrasonography, Doppler, Duplex; D014684:Venae Cavae / Q000000981:diagnostic imaging / Q000473:pathology; D014689:Venous Insufficiency / Q000175:diagnosis / Q000453:epidemiology*; D020246:Venous Thrombosis / Q000453:epidemiology; D014945:Wound Healing