Background: The role of pre-dilatation (balloon angioplasty before stent placement) versus direct stenting (non-predilatation) in carotid artery stenting (CAS) is unclear.
Aims: To assess whether systematic pre-dilatation with an adequately sized balloon can reduce the occurrence of Diffusion-Weighted Magnetic Resonance Imaging (DW-MRI)-detected ischemic lesions compared to direct stenting of the carotid artery (CAS).
Methods: Retrospective observational study including patients who underwent CAS with distal embolic filter protection and DW-MRI before and 24 to 48 hours post procedure. Procedural outcome, occurrence, number, and volume of new ischemic DW-MRI-detected lesions after CAS were compared depending on whether CAS was performed with or without pre-dilation with a balloon size according to the vessel diameter.
Results: The study includes 185 patients, 100 underwent CAS without (Cohort A) and 85 with pre-dilatation (Cohort B). Beside a higher degree of baseline carotid stenosis in cohort B, the other variables potentially impacting the occurrence of new ischemic lesions did not differ significantly. There were no differences in clinical outcome at 30 days (2 major stroke, 1 death in cohort A, 2 minor strokes in cohort B). Pre-dilatation of non-ulcerated carotid stenoses reduced the probability of new ischemic lesions independent of gender, symptom status, and lesion calcification, with the effect being most pronounced in diabetic patients, but had no impact in ulcerated stenoses. In non-ulcerated stenoses, the absence of pre-dilatation increased the odds of a higher number of ischemic lesions in calcified stenoses and was associated with a greater mean lesion volume in older patients and those with higher degrees of calcification. Based on a model incorporating the main effects of the variables on the occurrence of ischemic lesions and all interaction effects with pre-dilatation, pre-dilatation of non-ulcerated carotid stenosis reduced the probability new ischemic lesions by 34%.Conclusions: In this retrospective observational study, pre-dilatation of non-ulcerated carotid stenoses prior filter-protected CAS reduced the occurrence, the number, and volume of new DW-MRI-detected ischemic lesions. The clinical relevance of this finding needs to be validated by randomized trials.
