Carotid artery surgery and the principle of prophylaxis: recurrence in operated and nonoperated patients.

A total of 700 carotid endarterectomies have been performed over a 24-year period at the authors' institute; of these patients 632 (90.3%) had unilateral and 68 (9.7%) had bilateral disease. Some 71 patients who declined operation were followed-up to obtain the natural history of carotid disease. The operative results were compared against this untreated group of patients. Surgical endarterectomy was recommended for a recovered stroke in 190 patients (27.1%), progressive ischaemia in 20 (2.9%) and transient ischaemic attacks in 410 (58.6%). A group of 100 patients with non-specific symptomatology, who were considered 'symptom-free', were also operated on; none of these died or developed permanent postoperative neurological defects. The mean age of patients was 56 (range 28-86) years. The overall operative mortality rate was 0.8%. Perioperative neurological deficits occurred in 0.5% and temporary cranial nerve injury in 1.8%. The follow-up covered a period of 10 years, but was in several instances extended to 14 years. The incidence of late neurological events in the patients having an endarterectomy was 3%. In the non-operated group, 12% of normotensive and 18% of hypertensive patients developed symptoms. The 10-year postoperative survival rate was 80% in the symptom-free group of patients, 70% in those with transient ischaemic attacks and 60% in those who had a previous stroke.