DEVELOPMENT OF A MINIMALLY INVASIVE TECHNIQUE FOR CORONARY REVASCULARIZATION IN A PORCINE MODEL

Background. This porcine model was designed to develop a minimally inv asive method for internal mammary artery (IMA) grafting using an anter ior mediastinal approach and without routine use Of cardiopulmonary by pass. Methods. Assessment was made of IMA mobilization through a small parasternal incision, the feasibility of coronary artery grafting wit h cardiopulmonary bypass using this approach, and conditions for off-p ump bypass grafting. Results. In group 1, 6 Figs underwent IMA mobiliz ation through a 5-cm horizontal midparasternal incision. Of the 2 grou p 2 pigs, 1 underwent IMA grafting to the left anterior descending cor onary artery and the other, bilateral IMA grafting to the left anterio r descending and right coronary arteries using femoral-vessel cardiopu lmonary bypass. In group 3, 4 of 10 pigs had successful off-pump graft ing during retrograde regional coronary venous perfusion of arterial b lood. Retrograde coronary venoms perfusion could not be established in the other 6 pigs, and attempts at off-pump grafting failed. Conclusio ns. The study demonstrates that coronary artery grafting with the IMB by this minimally invasive off-pump method is feasible, although it dr aws attention to areas of concern and potential methods of correction. The model provides a realistic and important learning platform for th e surgical issues involved with this minimally invasive technique. (C) 1997 by The Society of Thoracic Surgeons.