Carotid endarterectomy after noninvasive evaluation by duplex ultrasonography and magnetic resonance angiography.

Recent studies documenting the efficacy of carotid endarterectomy (CEA) in selected patients provide further impetus for developing noninvasive techniques to evaluate carotid occlusive disease. Eliminating the morbidity due to preoperative angiography would further refine the treatment of this condition. Recent improvements and greater experience with magnetic resonance angiography (MRA) of extracranial vessels have increased the accuracy of this technique. We present our experience using MRA in combination with duplex ultrasonography as the primary mode of preoperative evaluation for CEA. Fifty-two patients referred for CEA underwent these two studies. In 47 patients (90%), significant stenosis (> 70%) was unambiguously identified on both ultrasound and MRA. Forty-one of these patients underwent CEA on the basis of these studies alone, without conventional angiography. In all of these cases, significant stenosis was identified at the time of surgery (100%), and CEA was performed without difficulty or complications. In five cases (9.6%), the MRA and ultrasound findings did not concur exactly. In three of these cases, the interpretation of the two studies differed with respect to the severity of stenosis; in the others, one of the studies was indeterminate. These patients underwent conventional angiography before surgery. Our experience suggests that the combined use of MRA and ultrasonography affords an accurate noninvasive evaluation of carotid occlusive disease sufficient for surgical planning in most cases.