[Duplex and transcranial sonography in the preoperative evaluation of cerebrovascular circulation before heart operations].

Fifty unselected patients undergoing open heart surgery (OHS) were examined by duplex and transcranial Doppler sonography. Two high degree (greater than 75%) carotid stenosis were found in 70 carotid arteries of 35 patients with coronary artery disease. Fourteen vessels had unmistakable signs of extracranial vascular disease whilst 54 carotid arteries were identified as normal. Two high degree (greater than 75%) carotid stenosis were found in 30 vessels of 15 patients with valvular disease. Seven other vessels had a low grade stenosis or excessive atheroma, whereas 21 were identified as normal. The rate of about 5-10% asymptomatic high grade carotid stenosis in patients undergoing OHS justifies routine noninvasive examination of the cerebral circulation by duplex and transcranial Doppler sonography. Patients with high grade stenosis are offered a follow-up preventive programme against cerebral infarction, which consists of 3 steps: 1. anti-platelet aggregating drugs, 2. periodic control examinations by duplex and transcranial Doppler sonography, and 3. continued evaluation of indication for carotid endarterectomy.