title: An experimental model of the Ross operation: Development of resorbable reinforcements for pulmonary autografts.
abstract: OBJECTIVE
  To circumvent the issue of pulmonary autograft (PA) dilation after the Ross procedure, surgical reinforcement strategies have been suggested in clinical or anecdotal series. However, no preclinical large-animal model of the Ross procedure is available, which is needed to enable full comprehension of the pathologic mechanisms and the effectiveness of reinforcement techniques during growth. Our aim was to develop a large-animal model of the Ross operation, to reproduce the clinical scenario in which this procedure might be applied, and allow for development and testing of various devices and techniques to improve PA performance. In addition, we aimed to test the effectiveness of a bioresorbable mesh for PA reinforcement.
  
  
  METHODS
  An experimental model of transposition of the pulmonary trunk as an autograft in the aortic position has been developed and performed under cardiopulmonary bypass in 20 growing lambs, aged 3 months. The experimental design included: a control group that underwent PA transposition; a group in which the PA was reinforced with an external, synthetic, nonresorbable, polypropylene grid; and a group that received various combinations of resorbable meshes. Animals were followed up during growth for 6 months by angiography and echocardiography and eventually killed for pathologic analysis.
  
  
  RESULTS
  All animals survived the procedure with no complications. The model was easy and reproducible. Resorbable meshes prevented PA dilation and preserved its progressive growth process, aiding histologic remodelling.
  
  
  CONCLUSIONS
  We developed an easy and reproducible model of the Ross procedure, allowing for a reliable simulation of the clinical scenario. Resorbable PA reinforcement may represent an interesting option in this context.
authors: Cardiac Surgery Centre Cardiologique du Nord de Saint-Denis, Paris, France. Electronic address: francesconappi2@gmail.com.
authors: Francesco
authors: F
authors: Nappi
authors: Department of Cardiothoracic Surgery, Golden Jubilee National Hospital, Clydebank, Glasgow, United Kingdom.
authors: Cristiano
authors: C
authors: Spadaccio
authors: Department of Pathology, Hôpital de la Salpétrière, Paris, France.
authors: Pierre
authors: P
authors: Fouret
authors: Department of Cardiology, Hôpital de la Salpétrière, Paris, France.
authors: Nadjib
authors: N
authors: Hammoudi
authors: Laboratory of Biosurgical Research, Carpentier Foundation, Pompidou Hospital, University Paris Descartes, Paris, France.
authors: Juan Carlos
authors: JC
authors: Chachques
authors: Department of Cardiovascular Surgery, University Campus Bio-Medico of Rome, Rome, Italy.
authors: Massimo
authors: M
authors: Chello
authors: Department of Cardiovascular Surgery, Hôpital de la Salpétrière, Paris, France.
authors: Christophe
authors: C
authors: Acar
mesh_terms: D020341:Absorbable Implants; D000367:Age Factors; D000818:Animals; D001013:Aorta, Thoracic / Q000601:surgery*; D064592:Autografts; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation*; D002315:Cardiopulmonary Bypass; D004108:Dilatation, Pathologic; D017548:Echocardiography, Transesophageal; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation*; D023421:Models, Animal; D011183:Postoperative Complications / Q000517:prevention & control; D011474:Prosthesis Design; D011651:Pulmonary Artery / Q000000981:diagnostic imaging / Q000473:pathology / Q000637:transplantation*; D011664:Pulmonary Valve / Q000000981:diagnostic imaging / Q000473:pathology / Q000637:transplantation*; D011859:Radiography; D012756:Sheep; D013526:Surgical Mesh; D013997:Time Factors; D066253:Vascular Remodeling