Imaging features of microembolization after carotid artery stenting and its influencing factors

Objective To investigate the incidence, location and influencing factors of new DWI lesions (NDWIL) on diffusionweighted magnetic resonance imaging (DW-MRI) after carotid artery stenting (CAS). Methods Patients admitted to department of neurology, Chinese PLA General Hospital from April 2016 to August 2017 who had undergone carotid artery stenting with cerebral protection device were enrolled in our study. Preoperative MRI examinations and 4 MRI follow-ups (24 h to 96 h after surgery) were performed. According to the manifestation of postoperative 24-hour imaging, patients were divided into NDWIL group and non-NDWIL group. The number and location of NDWIL within 96 hours after operation were recorded, and the clinical and laboratory data of NDWIL group and non-NDWIL group were compared. Results Of the 27 patients enrolled in this study, 25 were males and 2 were females with the average age of (63.1±5.3) years. NDWIL was detected in 18 (66.7%) patients at 24 h after CAS. Among them, only one patient developed visual rotation, nausea, vomiting, new nystagmus within 24 h after surgery, and the others only had subclinical embolisms. Totally 11 (40.7%) patients experienced increased number of NDWIL detected by MRI imaging at 24 h after surgery. Univariate analysis found that BMI of NDWIL group was higher than that of non-NDWIL group (P< 0.01). Conclusion Microembolization after CAS is a common clinical phenomenon, most of which are subclinical embolism without associated clinical defects. It occurs both during and after CAS. BMI index may be a risk factor.