title: Correction of aortic insufficiency with an external adjustable prosthetic aortic ring.
abstract: OBJECTIVE
  Less invasive, valve-sparing options are needed for patients with aortic insufficiency (AI). We sought to evaluate the feasibility of reducing AI with an external adjustable aortic ring in an ovine model.
  
  
  METHODS
  To create AI, five sheep underwent patch plasty enlargement of the aortic annulus and root by placement of a 10 x 15 mm pericardial patch between the right and noncoronary cusps. An adjustable external ring composed of a nylon band was fabricated and placed around the aortic root.
  
  
  RESULTS
  Aortic flow, aortic pressure, and left ventricular pressures were measured with the ring loose (off) and tightened (on). Mean regurgitant orifice area decreased by 86%, from 0.07 +/- 0.03 cm2 (ring loose, off) to 0.01 +/- 0.00 cm2 (ring tightened, on) [p < 0.01]. The regurgitant fraction decreased from 18 +/- 4% to 2 +/- 1% [p < 0.01]. The ring did not significantly affect stroke volume and aortic pressure.
  
  
  CONCLUSIONS
  An ovine model of aortic root dilatation resulting in acute AI has been developed. In this model, application of an external, adjustable constricting aortic ring eliminated AI. An aortic ring may be a useful adjunct in reducing AI secondary to annular dilatation.
authors.affiliation: Division of Cardiac Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Gogbashian
authors.forename: Ravi K
authors.initials: RK
authors.lastname: Ghanta
authors.forename: Ramanan
authors.initials: R
authors.lastname: Umakanthan
authors.forename: Aravind T
authors.initials: AT
authors.lastname: Rangaraj
authors.forename: Rita G
authors.initials: RG
authors.lastname: Laurence
authors.forename: John A
authors.initials: JA
authors.lastname: Fox
authors.forename: Lawrence H
authors.initials: LH
authors.lastname: Cohn
authors.forename: Frederick Y
authors.initials: FY
authors.lastname: Chen
mesh_terms: D000818:Animals; D001011:Aorta / Q000473:pathology / Q000601:surgery*; D001021:Aortic Valve / Q000601:surgery*; D001022:Aortic Valve Insufficiency / Q000473:pathology / Q000601:surgery*; D018618:Echocardiography, Doppler, Color; D006350:Heart Valve Prosthesis; D012756:Sheep