Methods: Three-hundred patients (232 males, 68 females; mean age 62.7±9.3 years; range 31 to 79 years) in whom CABG surgery was planned were enrolled in the study. In all patients, preoperative carotid and vertebral color Doppler ultrasonography (CDUS) was performed. The patients were preoperatively questioned for the risk factors for carotid artery stenosis and stroke, namely age, gender, smoking, diabetes mellitus, hypertension, hypercholesterolemia, previous stroke, the number of diseased coronary arteries and previous myocardial infarction. The carotid artery stenoses were classified as normal, mild (<50%), moderate (50-69%), severe (70-99%) and occlusion. A total vertebral artery flow volume below 200 ml/min was accepted as VBI. Cranial computed tomography without contrast was used for the diagnosis of postoperative stroke. The localizations and stages of the lesions were determined.

Results: Carotid lesion was detected in 83% of the patients. Significant stenosis (≥50%) and total occlusion were found in 15.3% and 2.3% of the patients, respectively. Vertebrobasilary insufficiency was detected in 29% of the patients. Seven (2.3%) patients had postoperative stroke, five of them were in the anterior and two of them were in the the posterior system. Stroke was found to be significantly related to ≥50% carotid stenosis, and stroke history, whereas no significant relation was found between VBI and stroke. In postoperative period one of the four deaths (1.3%) was caused by stroke. The mortality rate in patients who had postoperative stroke was 14.2%. While no stroke was observed in seven of 19 patients with high-grade stenosis and oclusion who underwent CEA, stroke was seen in two of the 12 patients who did not undergo CEA had stroke.

Conclusion: It is highly important to evaluate carotid stenosis with CDUS, which is the most important risk factor for stroke as it increases the mortality rate 10 folds after CABG operation. Treating the carotid lesions with CEA reduces the stroke incidence and mortality rate.