Abstract 344: Novel technique for endovascular biopsy of carotid endothelial cells in carotid artery stenosis: Proof of Concept & Follow Up of SVIN 2023 Pilot Grant

Introduction Acute ischemic stroke remains to be one of the top causes for morbidity and mortality among the general population, with approximately 800,000 strokes occurring per year nationwide. While the potential etiologies of stroke are numerous, 15‐20% of all strokes are attributed to carotid artery stenosis. While isolated studies have been conducted sampling carotid plaques after CEA, there is a dearth of literature examining the characteristics of the endoluminal cells and their molecular characteristics (such as transcriptomes) in carotid artery disease. We therefore employed a novel method for endovascular biopsy of carotid endothelial cells in the setting of carotid artery stenosis. Methods A prospective registry of adult patients undergoing endovascular treatment for carotid artery stenosis was maintained from January 2024 to August 2024. Informed consent was obtained, and at the conclusion of the case, critical devices were collected and placed in dissociation buffer including the access wire/sheath tip, the distal embolic protection device, and any balloons utilized for balloon angioplasty. Cells were then washed from the samples using a series of centrifugation, wash, and pelleting steps. Once completed, the pellet was then resuspended in a solution containing Hibernate A, and a standard antibody staining and sorting protocol was performed utilizing fluorescence activated cell sorting (FACS) to identify endothelial cells (via CD31 antibodies) and to exclude white blood cells (negative sorting via CD45 antibodies). Results Six patients met inclusion criteria and gave consent for endothelial carotid biopsy. After sorting for endothelial cells via FACS, the mean number of endothelial cells collected from the access sheath/wire was 1506 cells per patient. Similarly, the mean number of endothelial cells collected from the balloons utilized for angioplasty was 1124 cells. Finally, the mean number of endothelial cells collected from the distal embolic protection device was 5021 cells per patient. Discussion The preliminary findings herein suggest that this method of endovascular biopsy may very well be a reliable method for collecting endothelial cells from the carotid artery in the setting of treatment for carotid artery stenosis. Sample collection is still ongoing to further support the viability of this technique. Collected endothelial cells will then undergo RNA sequencing in order to describe the transcriptomic profile present in endothelial cells of diseased carotid arteries.