Background Recent randomized controlled trials have demonstrated similar outcomes in terms of ischemic stroke incidence after carotid endarterectomy (CEA) or carotid artery stenting (CAS) in asymptomatic carotid disease, while CEA seems to be the first option for symptomatic carotid disease. The aim of this meta-analysis is to assess incidence of silent cerebral microembolization detected by Magnetic Resonance Imaging (MRI) following these procedures.

Methods A systematic search was conducted using PubMed, Scopus and Cochrane databases including comparative studies involving symptomatic or asymptomatic patients undergoing either CEA or CAS, and reporting on new cerebral ischemic lesions in post-operative MRI. The primary outcome was the newly detected cerebral ischemic lesions. Pooled effect estimates for all outcomes were calculated using the random-effects model. Pre-specified random effects meta-regression and subgroup analysis were conducted to examine the impact of moderator variables on the presence of new cerebral ischemic lesions.

Results 25 studies reporting on total 1827 CEA and 1500 CAS interventions fulfilled the eligibility criteria. The incidence of new cerebral ischemic lesions was significantly lower after CEA comparing to CAS, regardless of the time of MRI assessment (first 24 hours; OR: 0.33, 95% CI: 0.17-0.64, p<0.001), (the first 72 hours, OR: 0.25, 95% CI 0.18-0.36, p<0.001), (generally within a week after the operation; OR: 0.24, 95% CI: 0.17-0.34, p<0.001). Also, the rate of stroke (OR: 0.38, 95% CI: 0.23-0.63, p<0.001) and the presence of contralateral new cerebral ischemic lesions (OR: 0.16, 95% CI 0.08-0.32, p<0.001) were less frequent after CEA. Subgroup analysis based on the study design and the use of embolic protection device during CAS showed consistently lower rates of new lesions after CEA.

Conclusions CEA demonstrates significant lower rates of new silent cerebral microembolization, as detected by MRI in postoperative period, compared to CAS.

The authors have declared no competing interest.

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