Background: The use of a distal filter cerebral protection device with carotid artery stenting is commonplace. There is little evidence, however, that filters are effective in preventing embolic lesions. This study examined the incidence of embolic phenomenon during carotid artery stenting with and without filter use.
Methods: This was a prospective, randomized, single-center study of carotid artery stenting with or without a distal cerebral protection filter. A 1:1 scheme was used to randomize 36 carotid artery stenting procedures in 35 patients. Diffusion-weighted magnetic resonance imaging (DW MRI) 24 hours after stenting was used to assess the occurrence of new embolic lesions. Blinded observers calculated lesion number and volume.
Results: The mean age was 78.6 +/- 7.0 in the cerebral protection group compared with 74.1 +/- 8.7 in the no cerebral protection group (P = .92). Despite similar average age, the percentage of octogenarians was higher in the cerebral protection group (61.1% vs 22.2%; P = .04). Two procedures in the cerebral protection group were not successful. One was completed without protection because of inability to track the filter, and the second was aborted because of severe tortuosity with a later carotid endarterectomy. New MRI lesions were noted in 72% of the cerebral protection group compared with 44% in the no cerebral protection group (P = .09). The average number of lesions in these patients was 6.1 and 6.2, respectively, with mean DW MRI lesion size of 16.63 mm(3) vs 15.61 mm(3) (P = .79 and .49, respectively). Four strokes occurred (11%), two in each group, in patients aged 75, 80, 82, and 84 years. The only major stroke occurred in the no cerebral protection group.
Conclusions: The use of filters during carotid artery stenting provided no demonstrable reduction of microemboli, as expected. Routine use of cerebral protection filters should undergo a more critical assessment before mandatory universal adoption.