Prophylactic carotid endarterectomy without arteriography in patients without hemispheric symptoms: surgical morbidity and mortality and long-term follow-up.

Between January 1980 and December 1992, 75 prophylactic carotid endarterectomies (CE) were performed on 72 asymptomatic patients presenting high-grade stenosis of the internal carotid artery (ICA). In all patients preoperative assessment consisted of continuous Doppler or duplex scanning. There were 33 women and 39 men with a mean age of 66 +/- 7 years. Surgical exploration confirmed high-grade ICA stenosis in all patients. Mean transstenotic gradient and residual carotid stump pressure determined in 24 patients were 34 +/- 25 mmHg and 51 +/- 20 mmHg, respectively. Combined operative mortality and neurologic morbidity was 1.3% (one death, no permanent neurologic defect). At 5 years, 74% +/- 8% of patients were free of neurologic complications, 89% +/- 8% of patients were free of neurologic complications affecting the ipsilateral cerebral hemisphere, and actuarial survival was 75% +/- 8%. Most deaths were due to heart-related causes. Multivariate analysis showed that hypertension, age, recurrent stenosis, and contralateral stenosis greater than 50% were risk factors for neurologic complications. When only ipsilateral complications were considered, only hypertension was a risk factor. Based on the results of this study, we conclude that prophylactic CE based only on continuous Doppler or duplex scanning is a reliable and safe procedure. Prophylactic CE was effective in avoiding long-term neurologic complications due to ipsilateral hemispheric lesions. However, the higher incidence of contralateral neurologic complications suggests that close surveillance of contralateral lesions is necessary.