E. Hitchner1, S. Rao1, S. Soman3, W. Zhou1,2 1VA Palo Alto Healthcare System,Vascular Surgery,Palo Alto, CA, USA 2Stanford University,Vascular Surgery,Palo Alto, CA, USA 3Harvard School Of Medicine,Radiology,Boston, MA, USA
Introduction: Cognitive change has been demonstrated in patients undergoing carotid interventions; however, the impact of these procedures on brain structure is unclear. Here we investigate how patient demographics and co-morbidities stratify differences in brain volume prior to and following carotid intervention.
Methods: Patients scheduled to undergo a carotid intervention were prospectively recruited under an IRB-approved protocol at a single academic center. Both patients undergoing carotid artery stenting (CAS) and carotid endarterectomy (CEA) were included. All subjects underwent pre- and post-operative MRI that included a T1 structural sequence. The T1 images were processed using FreeSurfer 5.3, with resulting segmentations reviewed and edited as needed under neuroradiologist supervision. Demographics were collected and analyzed to look for correlations with derived brain volumetrics.
Results:48 patients were recruited to the study; 42 completed all procedures and were included in the analysis. 99% of the patients were male with an average age of 70 years. As expected, older patients had smaller brain volume and larger ventricles. No significant relationships were found between change in brain segment volumes and procedure type (CAS vs. CEA), current smoking, or prior neurologic symptoms. History of alcohol abuse correlated with a decrease in caudal middle frontal volume (p=.04). Diabetics were found to experience a significant decrease in contralateral segment volumes, including the thalamus (p=.06), anterior cingulate (p=.01), and caudal middle frontal (p=.04) regions. Similarly, a relationship was found between patients with coronary artery disease (CAD) and a decrease in contralateral isthmus cingulate (p=.01) and rostral middle frontal volumes (p=.05). These changes were not replicated on the ipsilateral side, suggesting that revascularization may mitigate the effect of diabetes and CAD on brain structure.
Conclusion:Volumetric MRI data may provide insight on the impact of carotid interventions on the brain. Further work investigating this relationship is warranted.