Abstract 17394: A Novel Micro Computed Tomography Based Method for Assessing Ex Vivo Vascular Reactivity
Background: Vascular reactivity, including endothelial-dependent and endothelial-independent vasomotion, has been considered a primary determinant of the pathogenesis and severity of cardiovascular diseases including acute myocardial infarction and stroke. New methods for assessing vascular function in vivo have been utilized clinically; however, methodological advancement for in vitro and ex vivo has lagged. Micro-computed tomography (micro-CT) has emerged as a powerful and highly accurate imaging tool for biomedical research.
Objective: The aim of this study was to develop a new ex vivo method to assess vascular reactivity in isolated blood vessels using contrast enhanced micro-CT.
Methods: Porcine carotid arteries (n=10) were cannulated and perfused (15 ml/min) with Krebs solution containing contrast (20%). Arteries were equilibrated and scanned using micro-CT (GE eXplore CT120). Luminal volume was calculated from longitudinal reconstructions and normalized to vessel length. Contraction to norepinephrine (NE; 10-4M, 10-3M), acetylcholine (ACh; 10-7M, 10-6M) and relaxation to sodium nitroprusside (SNP; 10-3M) were calculated as % of baseline. Cross-sectional reconstructions provided qualitative assessment of luminal topography.
Results: All arteries were similar in length and volume at baseline (27.2±0.5mm and 9.5±0.5ul/mm2, respectively). Contraction-responses to low and high dose NE (62.7±8.5% and 51.3±5.0%, respectively) and ACh (61.1±11.8% and 51.0±21.1%, respectively) were similar. SNP-mediated relaxation increased volume (142.7±10.2%). Reconstructions are shown at baseline (A), and contracted with ACh (B, C).
Conclusions: Micro-CT imaging represents a novel and powerful method for measuring vascular function in isolated perfused arteries. Accurate evaluation of vascular reactivity in normal and diseased vessels can now be performed in device-implanted vessels using this new technique.
- © 2013 by American Heart Association, Inc.