Editor's Choice - Predictors of New Ischaemic Brain Lesions on Diffusion Weighted Imaging After Carotid Stenting and Endarterectomy: A Systematic Review.

ABSTRACT

OBJECTIVES: Peri-procedural ischaemic brain lesions on diffusion weighted imaging (DWI) after carotid endarterectomy (CEA) and carotid artery stenting (CAS) have been related to a higher chance of recurrent cerebrovascular events. This systematic review provides an overview of patient characteristics associated with increased risk of new DWI lesions. METHODS: MEDLINE, EMBASE, and Cochrane library databases were systematically searched (update November 2018) for studies reporting post-procedural DWI lesions after CEA or CAS. Data derived from both procedures were analysed separately. Studies reporting predictive features that were present prior to intervention were assigned to 10 categories age, gender, cardiovascular risk factors, symptomatology, plaque vulnerability, atherosclerotic burden, cerebrovascular haemodynamics, carotid/arch anatomy, inflammatory markers, and markers of coagulation. A semi-quantitative analysis was performed by plotting studies that found an association between the investigated features and DWI lesions against those that did not find an association. RESULTS: Forty-six studies (5018 patients) were included 10 reported only CEA, 33 CAS, and three both interventions. 68.0% of 1873 CEA patients and 55.9% of 3145 CAS patients were symptomatic. The weighted prevalence of DWI lesions was 18.1% (95% CI 14.0-22.7%) in CEA patients compared with 40.5% (95% CI 35.4-45.7%) in CAS patients. Studies reporting on CEA patients predominantly found an increased risk in symptomatic patients (two of seven studies, including 848/1661 patients), those with impaired haemodynamics (five of five studies), and increased inflammatory markers (two of three studies). Studies reporting on CAS patients often found a positive association with age (10/26 studies), high plaque vulnerability (25/34 studies), or complex carotid/arch anatomy (three out of five studies). CONCLUSIONS: For patients undergoing CEA, symptomatic status, impeded cerebral haemodynamics, and increased inflammatory markers are associated with increased susceptibility to peri-operative DWI lesions. In CAS patients, higher age, plaque vulnerability and complex carotid/aortic arch anatomy were identified as risk factors. These clinical predictors may assist with decision making on patient selection for medical treatment, CEA or CAS.