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Updated: Jan 16, 2026
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Published on: October 20, 2023
Structural and Mechanical Analysis of Treated and Untreated Aortic Coarctation in a Growing Porcine Model
Insights
Coarctation of the aorta (COA) intervention improves flow but not long-term health. Distal aortic tissue in a porcine model showed reduced interlamellar strength, indicating potential long-term mechanical issues despite minimal remodeling.
Area of Science:
- Cardiovascular Research
- Congenital Heart Defects
- Biomedical Engineering
Background:
- Coarctation of the aorta (COA) is a congenital heart defect requiring intervention.
- Successful COA treatment improves hemodynamics but doesn't eliminate long-term risks like hypertension.
- Understanding aortic tissue changes post-COA is crucial for long-term patient health.
Purpose of the Study:
- To investigate structural and mechanical differences in aortic tissue from a novel porcine model of COA.
- To evaluate the impact of a serially dilatable stent on aortic tissue.
- To compare findings with existing COA animal models, emphasizing physiological relevance.
Main Methods:
- Quantitative histologic analysis of aortic tissue structure.
- Mechanical testing including uniaxial, shear lap, and peel tests.
- Utilized a growing porcine model with induced and treated COA at relevant time points.
Main Results:
- No significant differences in elastin, collagen, or tissue/lumen area between sham, COA, and treated COA groups.
- Distal aortic tissue showed reduced circumferential failure peel tension in COA groups, suggesting decreased interlamellar strength.
- Proximal aortic tissue showed no significant structural or mechanical differences.
Conclusions:
- The growing porcine COA model demonstrated minimal adverse vascular remodeling.
- Reduced interlamellar strength in distal aortic tissue is a key finding, despite a lack of gross structural changes.
- Further research is needed to understand the mechanisms preventing remodeling and long-term implications.
Abstract:
Coarctation of the aorta (COA) is a congenital heart disease for which successful intervention can restore flow and reduce the blood pressure gradient, but does not ensure long-term health. Adults with successfully treated COA exhibit significantly higher incidence of hypertension. The objective of this study was to measure differences in the structure and mechanics of proximal and distal aortic tissue from a new, physiologically relevant growing porcine model of COA. This animal model also enabled the evaluation of a cutting-edge serially dilatable stent. Quantitative histologic analysis measured structural changes and the mechanical properties were investigated through uniaxial, shear lap, and peel tests of tissue from sham, control COA, and treated COA animals. Our original hypothesis that proximal aortic tissue from control and treated COA groups would be thicker and have less elastin was false. There were no significant differences in elastin content, collagen content, tissue area, lumen area, or lumen-to-tissue area between groups. Mechanically, distal tissue also exhibited no difference in either uniaxial or shear lap stiffness, failure stress, or failure strain between groups. Distal tissue from the COA control and treated COA groups however, exhibited, a lower circumferential failure peel tension, suggesting interlamellar strength was reduced. When compared with other previously published animal models of COA, a clear distinction was timing - our growing porcine model is the first for which COA was induced and treated at physiologically relevant time points. Our results indicated minimal adverse vascular remodeling in either the COA control or treated COA groups, however, it is unclear if this was due to a lack of severity, if elastinogenesis compensated for damage, or if another unknown mechanism prevented remodeling.
