title: An in vivo model of in situ implantation using pulmonary valved conduit in large animals under off-pump condition.
abstract: BACKGROUND
  The application of pulmonary valved conduit to reconstruct the continuity between right ventricles and pulmonary artery is one of the major surgeries. This study aimed to establish an in vivo model of in situ implantation using pulmonary valved conduit in large animals under off-pump condition to validate the long-term effects of artificial pulmonary valved conduit.
  
  
  METHODS
  Domesticate juvenile male sheep and tissue-engineered porcine pulmonary valved conduit were used for the experiment: 30 sheep, weighing (15 ± 3) kg (range 13 to 17 kg) were randomly divided into two groups which were all operated under general anesthesia by off-pump surgery (group 1) and left thoracotomy (group 2). Two different off-pump surgical methods were used to perform cannulation in sheep pulmonary artery to replace part of sheep pulmonary artery with pulmonary valved conduit which will work together with sheep pulmonary artery and valves. During the experiments, animal survival, complication rates, operating time and blood loss were recorded to compare the results between groups and to establish a surgical method with minimal invasion, simplicity, safety, and high success rates.
  
  
  RESULTS
  In group 1, a total of 15 cases of surgeries were performed, in which two sheep died; the operative mortality was 13.3% (2/15). In group 2, a total of 15 cases of surgeries were performed, and the surgical mortality rate was 0 (0/15). The operation time and blood loss in group 2 was significantly better than that in group 1. The postoperative echocardiograms showed that, after the surgeries by these two methods, the blood flows were normal, and the valves can open and close freely. Autopsy after 6 months showed that the inner wall and the valves of pulmonary valved conduit were smooth with no thrombus formation.
  
  
  CONCLUSIONS
  These two off-pump methods are feasible and safe with fewer traumas; but the second method is better and particularly suitable for the establishment of a juvenile animal model.
authors.affiliation: Department of Cardiac Surgery, Institute of Heart Lung and Blood Vessel Disease, Beijing Anzhen Hospital, Capital Medical University, Beijing 100029, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Wu
authors.forename: Zhi-wei
authors.initials: ZW
authors.lastname: Xu
authors.forename: Xian-min
authors.initials: XM
authors.lastname: Liu
authors.forename: Da
authors.initials: D
authors.lastname: Gong
authors.forename: Ju-yi
authors.initials: JY
authors.lastname: Wan
authors.forename: Xiu-fang
authors.initials: XF
authors.lastname: Xu
authors.forename: Zi-fan
authors.initials: ZF
authors.lastname: Zhou
authors.forename: Wen-bin
authors.initials: WB
authors.lastname: Li
mesh_terms: D000818:Animals; D006350:Heart Valve Prosthesis; D008297:Male; D011664:Pulmonary Valve; D012756:Sheep; D013552:Swine; D023822:Tissue Engineering