Beating-heart Coronary Artery Bypass Grafting Research Articles

Beating-heart endoscopic coronary artery surgery

Summary We have developed a novel technique allowing closed-chest beating-heart coronary artery bypass grafting, and have used it successfully in two patients.

Temporary luminal arteriotomy seal: II. coronary artery bypass grafting on the beating heart

Background. This study assessed the feasibility of applying a temporary luminal arteriotomy seal during end-to-side coronary artery bypass grafting on the beating heart. Methods. In 18 consecutive pigs, the left internal mammary artery was grafted to the left anterior descending coronary artery, and the arteriotomy was temporarily sealed luminally by a 200-μm-thick polyurethane seal. Endothelial denudation, medial necrosis, and intimal hyperplasia were measured quantitatively and compared with conventionally sutured anastomoses (n = 4 pigs). Results. Insertion and retrieval of the seal required 28 ± 12 and 11 ± 6 seconds, respectively. Including the arteriotomy, coronary artery occlusion was limited to about 80 seconds. The seal provided a bloodless arteriotomy in all anastomoses with unimpeded coronary artery blood flow. Endothelial denudation was limited to two thirds of the circumference of the coronary artery. No medial necrosis was found. Intimal hyperplasia at the suture line was small, although more pronounced when compared with conventionally sutured anastomoses. Conclusions. In off-pump, beating-heart coronary artery bypass grafting, the temporary luminal arteriotomy seal provided a bloodless arteriotomy with negligible obstruction to coronary artery blood flow, and with a minimum of arterial wall damage. It is conceivable that this seal may expand the indications for coronary surgical procedures without cardiopulmonary bypass.

On-Pump, Beating-Heart Coronary Artery Operations in High-Risk Patients: An Acceptable Trade-off?

Current cardioplegic techniques do not consistently avoid myocardial ischemic damage in high-risk patients undergoing coronary artery bypass grafting. Alternatively, revascularization without cardiopulmonary bypass is not always technically feasible. We investigated whether an intermediary approach based on maintenance of a beating heart with cardiopulmonary bypass support but without aortic cross-clamping might be an acceptable trade-off. Thirty-seven consecutive patients underwent coronary artery bypass grafting (with an average of two grafts per patient) in a pump-supported, non-cross-clamped beating heart. Inclusion criteria were poor left ventricular function (18 patients; mean ejection fraction, 0.25), evolving myocardial ischemia or infarction (11 patients, 5 of whom were in cardiogenic shock), and advanced age (3 patients; mean age 79.5 years) with comorbidities. Results were assessed primarily on the basis of clinical outcome. In addition, measurements of plasma levels of markers of myocardial damage (troponin Ic) and systemic inflammation (interleukin-6, interleukin-10, elastase) were done in 9 patients before and after bypass. In 6 patients, right atrial biopsy specimens were taken before and after bypass and processed by Northern blotting for the expression of messenger ribonucleic acid coding for the cardioprotective heat-shock protein 70. These biologic data were compared with those from control patients who underwent warm cardioplegic arrest within the same time span. There was one cardiac-related death (2.7%), one Q-wave myocardial infarction, and no strokes. Four other deaths occurred from noncardiac causes, yielding an overall mortality rate of 13.5%. Limitation of myocardial injury was demonstrated by the minimal increase in postoperative troponin Ic levels (3.3 +/- 1.0 micrograms/L versus 6.6 +/- 1.5 micrograms/L in controls; p < 0.05) and the finding that heat-shock protein 70 messenger ribonucleic acid levels (expressed as a percentage of an internal standard) were significantly increased after bypass compared with pre-bypass values (279% +/- 80% versus 97% +/- 21%; p < 0.05). In the control group (cardioplegia), end-arrest values of heat-shock protein 70 messenger ribonucleic acid were not significantly changed from baseline (148% +/- 49% versus 91% +/- 29%), a finding suggesting a defective adaptive response to surgical stress. Conversely, peak levels of inflammatory mediators were not significantly different between the two groups. The eight grafts to the left anterior descending coronary artery that were assessed angiographically, by transthoracic Doppler echocardiography, or both methods were patent with satisfactory anastomoses. In select high-risk patients, on-pump, beating-heart coronary artery bypass grafting may be an acceptable trade-off between conventional cardioplegia and off-pump operations. It is still associated with the potentially detrimental effects of cardiopulmonary bypass but eliminates intraoperative global myocardial ischemia.

Febrile Seizures

Coronary artery disease (CAD) is commonly associated with abdominal aortic aneurysms (AAAs) in elderly patients. When severe CAD requiring coronary artery bypass grafting (CABG) is associated with an impending AAA in a high-risk patient, the options for the suitable timing of CABG and AAA repair strategy (one-stage or two-stage) are still being debated.An 87-year-old man with non-ST-segment elevation myocardial infarction and a giant abdominal aortic aneurysm was transferred to our centre. Coronary angiography revealed triple-vessel coronary disease, and computed tomography confirmed a giant infrarenal fusiform abdominal aortic aneurysm 9 cm in maximal diameter. We simultaneously performed endovascular aneurysm repair prior to on-pump beating-heart coronary artery bypass grafting. The postoperative course was uneventful, and the patient was discharged on the 15th postoperative day.Combined endovascular aneurysm repair and on-pump beating heart coronary artery bypass grafting in a one-stage operation is a promising strategy to improve therapeutic efficiency in octogenarians. More studies are needed to compare the efficacy and safety of one-stage and two-stage operations to treat concomitant coronary artery disease and aortovascular pathology in the high-risk octogenarian patients.