Background: One major issue related to carotid artery revascularization procedures is their potential for inducing disturbances in blood brain barrier (BBB) permeability, which is considered to play a critical role in the pathophysiology of hyperperfusion syndrome. In this study, our aim was to evaluate the predictors of impaired BBB permeability and its topographic distribution among patients undergoing carotid artery stenting.
Methods: Clinical information (including demographic data, cardiovascular risk factors, degree of stenosis, indication and timing of the procedure), together with pre- and immediate post- (<24 hours) procedural magnetic resonance imaging (MRI) data was prospectively collected in a consecutive series of patients. BBB integrity was specifically evaluated on post-contrast FLAIR sequences. Regions of contrast extravasation were semi-automatically outlined and co-registered to a standard template in order to determine the topography of BBB disruption.
Results: Evidence for BBB disruption was observed in 11 out of 43 patients (26%) prior to stenting, a feature that was solely related to a recent history of ischemic stroke (<30 days) in multivariate analysis (p=0.033). New-onset or increased BBB disruption following the procedure was seen in 22 patients (51%); increased permeability was primarily observed in the ipsilateral cortical watershed territories (Figure) and was inversely related to the duration elapsed between carotid revascularization and MRI (p=0.036). Hyperperfusion syndrome developed in 7% of our patients, all of whom also having evidence of increased BBB permeability on post-stenting MRI.
Conclusion: Our findings highlight that BBB disruption in the peri-stenting setting is a frequently common observation, with specific spatial and temporal characteristics. Its predictive utility for predicting hyperperfusion syndrome and unfavorable clinical course, on the other hand, is fairly low.