Silent cerebral ischemic lesions after carotid artery stenting with distal cerebral protection

OBJECTIVE: To evaluate by MR diffusion weighted image (DWI-MR) the presence of new ischemic cerebral lesions after carotid artery stenting (CAS) and distal cerebral protection, in patients with internal carotid artery (ICA) stenosis >70. METHODS: Sixty-seven CAS were performed under cerebral protection with a distal filter. Mean age of the patients was 68.3 years (range 37-86) and 42 patients (62.7%) were symptomatic. An EZ filter device was used in all cases. The mean length of the procedure was 22.2 minutes (range 8-110). All patients had a cerebral MRI done in the 3 days before CAS and a DW-MR (eco planar single shot, b=1000 mm2/seconds) was done the day after. RESULTS: As a consequence of the CAS, three transient ischemic attacks were observed. There was one minor stroke (1.5%) on day 21, but no major stroke, death or myocardial infarction in a 30-day period. DW-MRI after CAS showed 26 new silent ischemic lesions in 11 asymptomatic patients (16.4%). In six, they were multiple (range 2-5). Lesions were mainly seen in the ipsilateral medial cerebral artery (21); four in the posterior fossa, and one in the contralateral medial cerebral artery. DISCUSSION: Although the use of distal cerebral protection was safe, new cerebral ischemic lesions, supposedly embolic, were observed in 16.4% of the patients. Although without clinical consequences in our series, their moderate high incidence should promote the investigation of safer techniques and devices.