title: Port-access bilateral internal mammary artery grafting for left main coronary artery disease: canine feasibility study.
abstract: BACKGROUND
  To extend the applications of minimal access cardiac surgery, an endovascular cardiopulmonary bypass (CPB) system that allows cardioplegia delivery and cardiac venting was used to perform bilateral internal mammary artery (IMA) bypass grafting in six dogs.
  
  
  METHODS
  The left IMA (LIMA) was taken down thoracoscopically from three left lateral chest ports, followed by the right IMA (RIMA) from the right side. One left-sided port was extended medially 5 cm with or without rib resection, to expose the pericardium. Both IMAs were divided and exteriorized through the left anterior mediastinotomy. Flow and pedicle length were satisfactory in all cases. Femoral-femoral bypass was used and the heart arrested with antegrade delivery of cardioplegic solution via the central lumen of a balloon catheter inflated to occlude the ascending aorta. All anastomoses were made through the mediastinotomy under direct vision. In five studies the RIMA was attached to the left anterior descending artery (LAD) and the LIMA to the circumflex, and in one study the RIMA was tunneled through the transverse sinus to the circumflex and the LIMA was anastomosed to the LAD. All animals were weaned from CPB in sinus rhythm without inotropes. CPB duration was 108 +/- 27 minutes (mean +/- SD) and the clamp duration was 54 +/- 10 minutes.
  
  
  RESULTS
  Preoperative and postoperative cardiac outputs were 2.9 +/- 0.71/min and 2.4 +/- 0.31/min, respectively (p = NS), and corresponding pulmonary artery occlusion pressures were 6 +/- 3 mmHg and 7 +/- 2 mmHg, respectively (p = NS). All 12 grafts were demonstrated to be fully patent. Postmortem examination revealed well aligned pedicles and correctly grafted target vessels.
  
  
  CONCLUSIONS
  This canine model demonstrates the potential for a less invasive approach to the surgical management of left main coronary artery disease in humans.
authors.affiliation: Department of Cardiothoracic Surgery, Standford University School of Medicine, CA 94305-5117, USA.
authors.forename: W S
authors.initials: WS
authors.lastname: Peters
authors.forename: T A
authors.initials: TA
authors.lastname: Burdon
authors.forename: L C
authors.initials: LC
authors.lastname: Siegel
authors.forename: M F
authors.initials: MF
authors.lastname: Pompili
authors.forename: J H
authors.initials: JH
authors.lastname: Stevens
authors.forename: F G
authors.initials: FG
authors.lastname: St Goar
authors.forename: H
authors.initials: H
authors.lastname: Reichenspurner
authors.forename: K
authors.initials: K
authors.lastname: Frischmeyer
authors.forename: R
authors.initials: R
authors.lastname: Cohen
authors.forename: B A
authors.initials: BA
authors.lastname: Reitz
mesh_terms: D000818:Animals; D001011:Aorta; D002302:Cardiac Output; D002408:Catheters, Indwelling; D003250:Constriction; D017023:Coronary Angiography; D003327:Coronary Disease / Q000503:physiopathology / Q000601:surgery*; D004285:Dogs; D005240:Feasibility Studies; D006324:Heart Arrest, Induced; D008323:Mammary Arteries / Q000637:transplantation*; D011184:Postoperative Period; D014654:Vascular Patency