SILENT BRAIN INFARCT AFTER CAROTID-ARTERY SURGERY - INCIDENCE AND PREVENTION

To determine the prevalence and mechanisms of postoperative silent bra in infarct, brain CT was routinely performed before and after carotid endarterectomy during the same period of hospitalization. Between June 1991 and May 1993, 69 patients who underwent 74 carotid endarterectom ies (five two-staged bilateral procedures) were enrolled in the study. Ipsilateral brain infarct was observed on the preoperative CT scans i n 25 cases. Of these 25 infarcts, three occurred in 20 patients (15%), without symptoms, 13 in 41 patients (32%) with transient ischemic att acks (TlAs), and 9 in 13 patients (70%) with cerebrovascular accident. After surgery, two patients (2.7% of procedures) had monoparesia of a n upper limb with no corresponding abnormality seen on CT scans, and t wo (2.7%) had TlAs, associated with CT evidence of a new lesion in one patient. Five silent brain infarcts (6.8%) were detected, including f our in the hemisphere contralateral to the restored carotid artery. Th ese study results indicate there is no correlation between the occurre nce of postoperative silent brain infarct and the presence of ulcerate d stenosis of the carotid artery documented by Doppler ultrasound exam ination. Silent infarct was not observed in any of the 24 patients (32 %) in whom a shunt had been used during the procedure. After a review of the literature, we propose wider use of intraoperative shunts to pr event postoperative silent brain infarct.