Strategies for preventing stroke after coronary artery bypass grafting

Abstract

To evaluate the usefulness of our strategy for preventing stroke after CABG, 343 consecutive patients were investigated retrospectively. Patient ages ranged from 32 to 31 years (mean; 63 +/- 9 years). There were 254 males and 59 females. Number of grafts per patient was 1 to 5 (mean 2.4 +/- 0.9 grafts). In 193 patients, internal carotid arteries (ICAs) were preoperatively evaluated by duplex scanning or cerebral angiogram. The degree of atherosclerosis in the ascending aorta was preoperatively examined by plain computed tomography in 181 patients, during surgery by ultrasonography in 75 patients and palpation in all patients. 1. On preoperative examination, there were 26 patients (15.1%) with ICA stenosis greater than 50% and 15 patients (7.8%) with stenosis greater than 75%. Six patients had bilateral ICA stenosis or occlusion greater than 75%. In 26 patients with ICA stenosis greater than 50%, history of stroke was significantly more prevalent than that in 167 patients without ICA stenosis (12 patients: 46.2% vs 22 patients: 13.1%, p < 0.001). In patients with ICA stenosis greater than 75%, 6 patients were symptomatic and 8 were asymptomatic. For these patients, concomitant carotid endarterectomy and CABG were performed in 5, two stage procedures in 7 reconstruction of cerebral perfusion followed by CABG;4, followed by CEA: 3), and CABG alone in 3. There was no stroke in any of these patients. 2. Atherosclerosis of the ascending aorta was found in 69 of 343 patients (20.1%). In these patients, single clamp technique was applied in 50 patients, aortic no touch technique in 12 and CABG without cardiopulmonary bypass in one. The arterial cannulation site was changed to femoral artery in 15 and to axillary artery in 6 patients. Statistical analysis indicated that age (older than 60 years) and history of stroke were significant risk factors for atherosclerotic ascending aorta. 3. There were 3 patients (0.9%) with perioperative stroke caused by embolism from the ascending aorta in one and hypoperfusion of the brain during cardiopulmonary bypass in two. Proper treatment of atherosclerotic ascending aorta and carotid occlusion may reduce the incidence of stroke in CABG patients.