PORT-ACCESS CORONARY-ARTERY BYPASS WITH CARDIOPLEGIC ARREST - ACUTE AND CHRONIC CANINE STUDIES

Background. Our goal is to perform minimally invasive coronary artery bypass grafting without sacrificing the benefits of myocardial protect ion with cardioplegia. Methods. Twenty-three dogs underwent acute stud ies and 4 dogs underwent survival studies. The left internal mammary a rtery was taken down using a thoracoscope. Cardiopulmonary bypass was conducted via femoral cannulas and using an endovascular balloon cathe ter for ascending aortic occlusion, root venting, and delivery of ante grade blood cardioplegia. Pulmonary artery venting was achieved with a jugular vein catheter. An internal mammary artery-to-coronary artery anastomosis was performed using a microscope through a 10 mm port. Res ults. All animals were weaned from cardiopulmonary bypass in sinus rhy thm without inotropes. Cardiopulmonary bypass duration was 104 +/- 28 minutes and aortic clamp duration was 61 +/- 22 minutes. Cardiac outpu t and pulmonary artery occlusion pressure were unchanged. The internal mammary artery was anastomosed to the left anterior descending artery (25) or the first diagonal (2) with patency shown in 25 of 27. One do g in the survival study had a very short internal mammary artery pedic le under tension and was euthanized for excessive postoperative hemorr hage. Three weeks postoperatively the remaining dogs had angiographica lly patent anastomoses, normal transthoracic echocardiograms, and hist ologically normal healing and patent grafts. Conclusions. Endovascular cardiopulmonary bypass using a balloon catheter is effective in arres ting and protecting the heart to allow thoracoscopic internal mammary artery-to-coronary artery anastomosis.