[Intraoperative evaluation of carotid endarterectomy with electromagnetic flowmetry and portable DSA]

In order to perform carotid endarterectomy more safely, we have evaluated, intraoperatively, the result of an operation with electromagnetic flowmeter and portable digital subtraction angiography (DSA). During surgery, flow of the exposed internal and common carotid artery was measured with an electromagnetic flowmeter, before and after endarterectomy. After the closure of the arteriotomy, portable DSA was carried out by injecting contrast medium from the common carotid artery. Our simple portable DSA system consists of a surgical X-ray television set, image processor (Sigma X) and still video-recorder. This system almost gives us a real-time presentation of a subtracted view of angiography. There were twenty patients including one patient with major stroke, 14 with minor stroke, three with transient ischemic attack, and two asymptomatic patients. Increase of the flow through the internal carotid artery was documented with an electromagnetic flow-meter in 13 of 20 patients following endarterectomy. Flow reduction was seen in two patients, one of whom was found to have an intimal flap from residual plaque visualized in the portable DSA. The plaque was removed by reopening the artery. Among twenty patients, intraoperative portable DSA showed an intimal flap in three patients and a step in four patients. Although the incidence of abnormal findings was high, degree of abnormality was not severe enough to reopen the artery except in one case. The purposes of carotid endarterectomy is two-fold. It is used for the removal of the plaques which can be a source of emboli, and also for the augmentation of flow in the narrowed segment of the artery.(ABSTRACT TRUNCATED AT 250 WORDS)