title: Evaluation of a percutaneously controlled hydraulic occluder in a rat model of gradual venous occlusion.
abstract: OBJECTIVE
  To evaluate the efficacy of a percutaneously controlled hydraulic occluder (HO) in a rat model of gradual venous occlusion.
  
  
  METHODS
  Experimental study.
  
  
  METHODS
  Ten male Sprague-Dawley rats.
  
  
  METHODS
  HOs and perivascular transit time ultrasound flow probes were applied to the caudal vena cava (CVC). Occluders in group I rats (n=6) were gradually attenuated over 8 weeks, whereas occluders in group II rats (n=4) were not attenuated. Vena caval blood flow measurements were performed weekly in all rats for 8 weeks. After euthanasia, the CVC was evaluated grossly and by histopathology.
  
  
  RESULTS
  Premature occlusion of the vena cava occurred during the 1st week in 3 rats (1 in group I, 2 in group II) because of kinking of the vena cava between the HO and the flow probe. For the remaining rats, mean blood flow in group I decreased significantly from 40.71 mL/min/kg at baseline to 4.68 mL/min/kg at 8 weeks (P=.0094, power=0.91). Group II rats maintained vena caval blood flow at all times during the study. Complete occlusion of the vena cava was confirmed at necropsy in all group I rats.
  
  
  CONCLUSIONS
  Gradual occlusion of the CVC of rats was achieved with HOs over 8 weeks. This model is limited by the size of the experimental animals and comparatively large implants.
  
  
  CONCLUSIONS
  HOs may provide a method for gradual occlusion of congenital portosystemic shunts.
authors.affiliation: Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610-0126, USA.
authors.forename: Colin W
authors.initials: CW
authors.lastname: Sereda
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Adin
authors.forename: Pamela E
authors.initials: PE
authors.lastname: Ginn
authors.forename: James P
authors.initials: JP
authors.lastname: Farese
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity / Q000662:veterinary; D004195:Disease Models, Animal; D008297:Male; D011168:Portal System / Q000002:abnormalities* / Q000601:surgery; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D016896:Treatment Outcome; D014682:Vena Cava, Inferior / Q000502:physiology / Q000601:surgery*