A minimally invasive port-access system successfully allowed anastomosis of the internal thoracic artery to the left anterior descending coronary artery in 9 of 10 canine models.
Is port-access coronary artery bypass grafting without sternotomy or thoracotomy feasible in canine and cadaver models?
Port-access coronary artery bypass grafting with cardioplegic arrest without sternotomy or thoracotomy is technically feasible in preclinical models.
Minimally invasive surgical methods have been developed to provide patients the benefits of open operations with decreased pain and suffering. We have developed a system that allows the performance of cardiopulmonary bypass and myocardial protection with cardioplegic arrest without sternotomy or thoracotomy. In a canine model, we successfully used this system to anastomose the internal thoracic artery to the left anterior descending coronary artery in nine of 10 animals. The left internal thoracic artery was dissected from the chest wall, and the pericardium was opened with the use of thoracoscopic techniques and single lung ventilation. The heart was arrested with a cold blood cardioplegic solution delivered through the central lumen of a balloon occlusion catheter (Endoaortic Clamp; Heartport, Inc., Redwood City, Calif.) in the ascending aorta, and cardiopulmonary bypass was maintained with femorofemoral bypass. An operating microscope modified to allow introduction of the 3.5x magnification objective into the chest was positioned through a 10 mm port over the site of the anastomosis. The anastomosis was performed with modified surgical instruments introduced through additional 5 mm ports. In the cadaver model (n = 7) the internal thoracic artery was harvested and the pericardium opened by means of similar techniques. A precise arteriotomy was made with microvascular thoracoscopic instruments under the modified microscope on four cadavers. In three other cadavers we assessed the exposure provided by a small anterior incision (4 to 6 cm) over the fourth intercostal space. This anterior port can assist in dissection of the distal internal thoracic artery and provides direct access to the left anterior descending, circumflex, and posterior descending arteries. We have demonstrated the potential feasibility of grafting the internal thoracic artery to coronary arteries with the heart arrested and protected, without a major thoracotomy or sternotomy.
Stevens et al. (1996) studied Coronary artery bypass grafting (n=17). Port-access coronary artery bypass grafting was evaluated on Successful anastomosis of the internal thoracic artery to the left anterior descending coronary artery. A minimally invasive port-access system successfully allowed anastomosis of the internal thoracic artery to the left anterior descending coronary artery in 9 of 10 canine models.