Abstract T P238: Evaluating the Stent-Wall Interaction in a Hemodynamically Induced Swine Model of Carotid Atherosclerosis: Correlation of Pre-Treatment Black-Blood 3T MRI with Post-Stenting Histopathology
Introduction: We evaluated the histopathologic characteristics of the stented arterial segments in a swine model of carotid atherosclerosis.
Methods: Atherosclerotic plaque was created by inducing 80% stenosis via partial surgical ligation (without endothelial balloon injury) in combination with dietary hypercholesterolemia in a single Yucatan minipig (Fig A). High-resolution black-blood 3T MRI of both carotid arteries was obtained at 6 months. Stenting was performed immediately after imaging. The animal was sacrificed 4 weeks after stenting. Histopathologic and morphometric analysis was performed.
Results: MRI: Figure A. Contrast-enhanced MRA. B. Cross-sectional 2mm views of proton density (PD), T2, T1, T1 post contrast, and time-of-flight (TOF) sequences of the stenotic segments of the R (top) and L (bottom) carotid arteries.
The image characteristics of the R carotid stenosis are consistent with an American Heart Association Lesion Type IV/V. No athermoatous features are seen in the L carotid.
Histopathology: Moderate lymphocyte proliferation was noted in the narrowest mid-section (N-Mid) from the right carotid, corresponding to the depicted lesion on MRI. This segment had the smallest neointimal/thrombus thickness (Table). Only mild residual atherosclerosis was appreciated within the stent.
EEL - external elastic lamina
IEL - internal elastic lamina
Conclusions: Our findings indicate histologic reversibility of the MRI-defined carotid atherosclerotic lesion four weeks after stenting, possibly due to improved flow within the hemodynamically-induced plaque. Unlike prior studies, neointimal proliferation was least prominent at the pre-existing atheroma.
Author Disclosures: R. Raychev: None. M. Fujimoto: None. S. Tateshima: Consultant/Advisory Board; Modest; Covidien, Penumbra, Stryker, Reverse Medical, Pulsar Vascular.
- © 2015 by American Heart Association, Inc.