title: Cardioscopic tricuspid valve repair in a beating ovine heart.
abstract: BACKGROUND
  Open heart surgery is commonly associated with cardiopulmonary bypass and cardioplegic arrest. The attendant risks of cardiopulmonary bypass may be prohibitive in high-risk patients. We present a novel endoscopic technique of performing tricuspid valve repair without cardiopulmonary bypass in a beating ovine heart.
  
  
  METHODS
  Six sheep underwent sternotomy and creation of a right heart shunt to eliminate right atrial and right ventricular blood for clear visualization. The superior vena cava, inferior vena cava, pulmonary artery, and coronary sinus were cannulated, and the blood flow from these vessels was shunted into the pulmonary artery via a roller pump. The posterior leaflet of the tricuspid valve was partially excised to create tricuspid regurgitation, which was confirmed by Doppler echocardiography. A 7.0-mm fiberoptic videoscope was inserted into the right atrium to visualize the tricuspid valve. Under cardioscopic vision, an endoscopic needle driver was inserted into the right atrium, and a concentric stitch was placed along the posterior annulus to bicuspidize the tricuspid valve. Doppler echocardiography confirmed reduction of tricuspid regurgitation.
  
  
  RESULTS
  All animals successfully underwent and tolerated the surgical procedure. The right heart shunt generated a bloodless field, facilitating cardioscopic tricuspid valve visualization. The endoscopic stitch resulted in annular plication and functional tricuspid valve bicuspidization, significantly reducing the degree of tricuspid regurgitation.
  
  
  CONCLUSIONS
  Cardioscopy enables less invasive, beating-heart tricuspid valve surgery in an ovine model. This technique may be useful in performing right heart surgery without cardiopulmonary bypass in high-risk patients.
authors.affiliation: Division of Cardiac Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: Ramanan
authors.initials: R
authors.lastname: Umakanthan
authors.forename: Ravi K
authors.initials: RK
authors.lastname: Ghanta
authors.forename: Aravind T
authors.initials: AT
authors.lastname: Rangaraj
authors.forename: Lawrence S
authors.initials: LS
authors.lastname: Lee
authors.forename: Rita G
authors.initials: RG
authors.lastname: Laurence
authors.forename: John A
authors.initials: JA
authors.lastname: Fox
authors.forename: Tomislav
authors.initials: T
authors.lastname: Mihaljevic
authors.forename: Ralph M
authors.initials: RM
authors.lastname: Bolman
authors.forename: Lawrence H
authors.initials: LH
authors.lastname: Cohn
authors.forename: Frederick Y
authors.initials: FY
authors.lastname: Chen
mesh_terms: D000818:Animals; D053704:Capsule Endoscopy / Q000379:methods*; D013504:Cardiovascular Surgical Procedures / Q000379:methods*; D019651:Plastic Surgery Procedures / Q000379:methods*; D012756:Sheep; D014261:Tricuspid Valve / Q000601:surgery*