title: Aortic conduit valve model with controlled moderate aortic regurgitation in rats: a technical modification to improve short- and long-term outcome and to increase the functional results.
abstract: BACKGROUND
  The objective of this study was to describe a small animal aortic conduit model that could analyze long-term conduit valve (CV) function by echocardiography.
  
  
  RESULTS
  Recipient Wistar rats (200-250g, n=20) underwent aortic leaflet injury of their native aortic valve under echocardiographic control. After 2 weeks, U-shaped decellularized CVs obtained from other rats were implanted onto the abdominal aorta. Implanted CVs were analyzed via pulsed-wave echocardiography at day 0, 4 and 12 weeks. CV stenosis was assessed as systolic flow velocity (post-pre CV)/flow velocity in the ascending aorta. CV regurgitation was assessed as the ratio of the amount of reversed diastolic flow to forward systolic flow in post-pre CV. The endpoint was set at 12 weeks. Three rats died immediately after aortic valve injury and all surviving rats received CV implantation (n=17, 85%). The survival rate after conduit implantation was 100% at 4 weeks and 88% (15/17) at 12 weeks. Regarding the CV function at 0, 4 and 12 weeks, the average observed value of CV stenosis was 3.8±7.9%, 3.1±4.1% and 14±10% (P<0.01), respectively. The average value of CV regurgitation was 0%, 12±27% and 52±43%, respectively (P<0.001).
  
  
  CONCLUSIONS
  By using this model, the degeneration of implanted CV could be assessed not only qualitatively, but also quantitatively.
authors.affiliation: Department of Cardiovascular Surgery and Research Group for Experimental Surgery, Heinrich Heine University, Medical Faculty.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Munakata
authors.forename: Alexander
authors.initials: A
authors.lastname: Assmann
authors.forename: Bhawana
authors.initials: B
authors.lastname: Poudel-Bochmann
authors.forename: Kim
authors.initials: K
authors.lastname: Horstkötter
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kamiya
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Okita
authors.forename: Artur
authors.initials: A
authors.lastname: Lichtenberg
authors.forename: Payam
authors.initials: P
authors.lastname: Akhyari
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D001021:Aortic Valve / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D001022:Aortic Valve Insufficiency / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D004195:Disease Models, Animal; D008297:Male; D051381:Rats; D011917:Rats, Inbred Lew; D017208:Rats, Wistar; D014463:Ultrasonography