Background: Carotid artery stenting (CAS) leads to frequent embolic brain lesions; their source has not been clearly identified yet. In order to investigate this phenomenon, we have evaluated embolic brain lesions (BL) after CAS and correlated them with aortic arch (AA) characteristics.
Methods: The AAs of 59 patients undergoing CAS under distal protection were evaluated by angiography and transesophageal echocardiography (TEE). AAs were stratified according to morphology (type I and II "simple" vs type III and bovine "difficult"), atherosclerotic arch lesions (complicated: >5 mm or with mobile debris vs uncomplicated: <5 mm), and tortuosity index (TI; sum of all angles diverging from ideal carotid axis, <150 vs >150). Diffusion weighted imaging (DWI) was performed before and within 24 hours from CAS. New BL were considered ipsilateral (IL) if ipsilateral to the site of CAS and non-ipsilateral (CL) if contralateral to it or bilateral. Normality distribution was by Shapiro-Wilk test (variables reported as medians +/- interquartile range) and statistical significance (P < .05) by Wilcoxon and Fisher's exact test.
Results: Difficult arches were present in 17 patients (28.8%), complicated aortic plaque in 21 (35.5%), and TI > 150 in 34 (57.6%). New BL appeared in 34 or 57.6% patients (6 or 18% IL and 28 or 82% CL). The mean number of BL was 5.7 (range, 0 to 20), 4.7 IL, and 5.7 CL, with a median volume of 560.95 +/- 1677.7 mm(3). Type of arch and TI were not correlated with mean number of BL. Mean volume of BL were greater in patients with difficult AA, complicated plaques, and TI > 150 (258 (572) mm(3) vs 15.6 (353) mm(3), P = .2; and 86 (828) mm(3) vs 85.9 (352) mm(3), P = .4 172 (766) mm(3) vs 0 (228) mm(3), P = .06, respectively). In patients with all three AA characteristics, mean number and volume of BL was significantly greater compared with other patients. Specifically, this increase was due mainly to CL (IL 0 (117) mm(3) vs 0 (172) mm(3), P = .9; CL 564 (687) mm(3) vs 0 (133) mm(3), P = .001). None of the technical details considered was correlated with either IL or CL.
Conclusion: BL are frequent after protected CAS and are correlated with AA characteristics, thus underlining the role of catheterization maneuvers in determining embolic events. TEE may be useful in patient's selection for CAS.