Incidence of new brain lesions after carotid stenting with and without cerebral protection

Background and Purpose-Diffusion-weighted imaging (DWI) may be a useful tool to evaluate the efficacy of cerebral protection devices in preventing thromboembolic complications during carotid angioplasty and stenting (CAS). The goals of this study were (1) to compare the frequency, number, and size of new DWI lesions after unprotected and protected CAS; and (2) to determine the clinical significance of these lesions. Methods-DWI was performed immediately before and within 48 hours after unprotected or protected CAS. Clinical outcome measures were stroke and death within 30 days. Results-The proportion of patients with any new ipsilateral DWI lesion (49% versus 67%; P < 0.05) as well as the number of new ipsilateral DWI lesions (median=0; interquartile range [IQR] =0 to 3 versus median=1; IQR=0 to 4; P < 0.05) were significantly lower after protected (n=139) than unprotected (n=67) CAS. The great majority of these lesions were asymptomatic and less than 10 mm in diameter. Although there were no significant differences in clinical outcome between patients treated and not treated with protection devices (7.5% versus 4.3%, not significant), the number of new DWI lesions was significantly higher in patients who developed a stroke (median=7.5; IQR=1.5 to 17) than in patients who did not (median=O; IQR=1 to 3.25; P < 0.01). Conclusions-The use of cerebral protection devices significantly reduces the incidence of new DWI lesions after CAS of which the majority are asymptomatic and less than 10 mm in diameter. The frequent occurrence of these lesions and their close correlation with the clinical outcome indicates that DWI could become a sensitive surrogate end point in future randomized trials of unprotected versus protected CAS.