title: Characterization of a porcine model of chronic superficial varicose veins.
abstract: OBJECTIVE
  Previous animal models of venous disease, while inducing venous hypertension and valvular insufficiency, do not produce superficial varicose veins. In this study, we aimed to develop and characterize a pig-based model of superficial varicose veins.
  
  
  METHODS
  Right femoral arteriovenous fistulae (AVF) were surgically fashioned in young adult pigs. Animals were examined at postoperative times up to 15 weeks to determine the development of varicose veins and measurement of both blood pressure and flow velocities within the superficial thigh veins. Histology and vascular corrosion casts were used to characterize the resulting structural venous alterations. Porcine pathophysiological features were compared with those of human primary superficial varicose veins.
  
  
  RESULTS
  Gross superficial varicosities developed over the ipsilateral medial thigh region after an initial lag period of 1-2 weeks. Veins demonstrated retrograde filling with valvular incompetence, and a moderate, non-pulsatile, venous hypertension, which was altered by changes in posture and Valsalva. Venous blood flow velocities were elevated to 15-30 cm/s in varicose veins. Structurally, pig varicose veins were enlarged, tortuous, had valvular degeneration, and regions of focal medial atrophy with or without overlying intimal thickening.
  
  
  CONCLUSIONS
  The superficial varicose veins, which developed within this model, have a pathophysiology that is consistent with that observed in humans. The porcine femoral AVF model is proposed as a suitable experimental model to evaluate the pathobiology of superficial venous disease. It may also be suitable for the evaluation of treatment interventions including drug therapy.
authors.affiliation: Vascular Research Group, Surgery Department, University of Otago, Dunedin, New Zealand. greg.jones@otago.ac.nz
authors.forename: Gregory T
authors.initials: GT
authors.lastname: Jones
authors.forename: Mark W
authors.initials: MW
authors.lastname: Grant
authors.forename: Ian A
authors.initials: IA
authors.lastname: Thomson
authors.forename: B Geraldine
authors.initials: BG
authors.lastname: Hill
authors.forename: André M
authors.initials: AM
authors.lastname: van Rij
mesh_terms: D000818:Animals; D001166:Arteriovenous Shunt, Surgical; D001783:Blood Flow Velocity; D002908:Chronic Disease; D016319:Corrosion Casting; D004108:Dilatation, Pathologic; D004195:Disease Models, Animal; D018450:Disease Progression; D005263:Femoral Artery / Q000601:surgery; D005268:Femoral Vein / Q000601:surgery; D035002:Lower Extremity / Q000098:blood supply*; D012039:Regional Blood Flow; D012501:Saphenous Vein / Q000473:pathology / Q000503:physiopathology; D013552:Swine; D013997:Time Factors; D018615:Ultrasonography, Doppler, Color; D014648:Varicose Veins / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D014689:Venous Insufficiency / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D014690:Venous Pressure