[Carotid endarterectomy for prevention of stroke: comparison of surgical and conservative therapy].

The incidence of TIA, stroke and death among 689 patients with a narrowing of the internal carotid artery exceeding 50% was investigated in a follow-up study. Patients were assigned according to their initial status to one of the following groups: asymptomatic, transient ischemic attacks (TIA) and minor stroke. Patients subjected to carotid endarterectomy (n = 206) were compared to those treated by oral medication only. The follow-up time averaged 2.1 years. The incidence of stroke and death among the initially asymptomatic persons was not significantly different in those who underwent surgery (n = 46) and those who did not (n = 234). The incidence of TIA however was significantly higher in the operated patients. Among patients with TIA the incidence of repeated TIA, stroke and death was similar in those who were operated (n = 90) and those who were not (n = 61). The same was true for subsequent TIA and strokes in patients who had suffered from a first stroke prior to the initial examination. Patients who underwent surgery (n = 70) did not differ in this respect from the 188 patients who were not operated on. The death rate, however, was significantly higher in the non-operated patients (24.5% versus 7.2%). Due to the retrospective character of the study, operated and non-operated groups of patients were not directly comparable. We therefore selected comparable groups of patients by a stratification procedure. These subgroups showed no differences in the incidence of TIA and stroke between operated and non-operated patients. The result indicates, that the decision to perform carotid endarterectomy should be made with great caution.