Total Myocardial Revascularization without Cardiopulmonary Bypass Utilizing Computer-Processed Monitoring to Assess Cerebral Perfusion

Abstract

Background: Total myocardial revascularization without the use of cardiopulmonary bypass (CPB) has been easily achieved using a combination of: a) deep pericardial sutures, b) right pleural herniation, and c) controlled intermittent hypotension.

Methods: Five hundred fifty patients underwent revascularization off CPB, with 344 patients having three-vessel disease, 150 two-vessel disease, and 54 one-vessel disease. The use of controlled intermittent hypotension, adminis-tering esmolol and nitroglycerine during anesthesia greatly facilitated access to the marginal territory. The reduction of the systemic arterial blood pressure and the heart rate resulted in decreased ventricular wall stress. The heart was pliable, easy to manipulate, herniated into the right pleural cavity, and thus epicardial stabilization was achieved without inducing hemodynamic instability.

To avoid the potential detrimental effects of intermittent hypotension we used two continuous brain-monitoring techniques: a) cortical brain oxymetry (cerebro-venous oxygen saturation (CVOS)) and b) electroencephalographic spectral array (EEG). Brain oxymetry changes of more than 20% from baseline value were observed in 15% of patients and preceded the EEG changes observed in 6% of patients. A reduction of CVOS, more than 20% for one to two minutes from baseline values required pharmacological intervention with alpha agents. The combination of both CVOS and EEG required temporary placement of the heart back into the pericardial cavity. Normalization of CVOS and EEG to baseline values was always restored. Following recovery the addition of alpha agents and reduc-tion of drug dosage allowed successful cardiac herniation.

Results: We performed a total of 1,579 grafts on 1,389 VD, obtaining a ratio of 1.13 grafts for VD. In the entire group, there were 411 patients with circumflex disease who underwent 456 bypass grafts (ratio of 1.1). The stroke incidence was not significantly different than patients operated on using CPB.

Conclusions: We conclude that using CVOS and EEG monitoring during off CPB, CABG complete coronary revascularization including the obtuse marginal artery is routinely achieved.