Protective Biomechanical and Histological Changes in the False Lumen Wall in Chronic Type B Aortic Dissection
Presented During:
Thursday, April 25, 2024: 5:38PM - 7:00PM
Sheraton Times Square
Posted Room Name:
Central Park
Abstract No:
P0269
Submission Type:
Abstract Submission
Authors:
Hai Dong (1), Minliang Liu (1), Hannah Cebull (2), Marina Piccinelli (2), John Oshinski (3), John Elefteriades (4), Rudolph Gleason (1), Bradley Leshnower (5)
Institutions:
(1) Georgia Institute of Technology, Atlanta, GA, (2) Emory University, Atlanta, GA, (3) Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, (4) Yale New Haven Hospital, New Haven, CT, (5) Emory University Hospital, Atlanta, GA
Submitting Author:
Hai Dong
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Georgia Institute of Technology
Georgia Institute of Technology
Co-Author(s):
Minliang Liu
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Georgia Institute of Technology
Georgia Institute of Technology
Hannah Cebull
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Emory University
Emory University
Marina Piccinelli
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Emory University
Emory University
John Oshinski
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Department of Biomedical Engineering, Georgia Institute of Technology
Department of Biomedical Engineering, Georgia Institute of Technology
*John Elefteriades
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Yale New Haven Hospital
Yale New Haven Hospital
Rudolph Gleason
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Georgia Institute of Technology
Georgia Institute of Technology
*Bradley Leshnower
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Emory University Hospital
Emory University Hospital
Presenting Author:
Hai Dong
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Abstract:
Objective: The mechanical strength of the false lumen wall (FLW) prevents rupture in aneurysms secondary to Chronic Type B Aortic Dissection (CTBAD), despite having partial thickness. The FLW consists primarily of adventitia, a key component in the open repair of dissections. This study sought to elucidate mechanisms of FLW mechanical properties which remain unclear.
Methods: The FLW from 14 patients (9 CTBAD and 5 Acute Type A Aortic Dissection) who underwent open aortic replacement was analyzed, and compared to iatrogenically dissected, manually peeled FLW from 6 normal transplant donor descending aortas designated as a control group (C-FLW). Biaxial tension testing in the circumferential (Circ) and axial directions was performed on the CTBAD-FLW (n=9), Acute-A-FLW (n=5) and C-FLW (n=6) tissues. Stress-strain curves were created (Fig. 1a), and a lower and higher tangent modulus (LTM & HTM) was determined for each sample to assess tissue stiffness. A histologic analysis of the tissue microstructure was performed on the collagen and elastin fibers. Quantification of the composition of collagen and elastin fibers was performed by calculating the fibers' volume fraction (VF) from Z-Stack scans (n=106 locations in 15 FLW samples [5 per group], 4-9 locations per sample based on thickness).
Results: In Circ, both LTM and HTM of CTBAD-FLW were significantly larger than those of C-FLW and Acute-A-FLW (Fig. 1b, c). In axial, HTM of the FLW was also larger than that of C-FLW and Acute-A-FLW (Fig. 1c), and LTM of Acute-A-FLW was smaller than that of C-FLW (Fig. 1b). Histology demonstrated a higher concentration of organized collagen in CTBAD-FLW compared to C-FLW and Acute-A-FLW, and a lower concentration of elastin (Fig. 1d). Quantification of the collagen/elastin profile in the tissue demonstrated a significant increase in the VF of collagen fibers and a significant decrease in the VF of elastin fibers when comparing CTBAD-FLW versus Acute-A-FLW & control-FLW (Fig. 1e). The VF of collagen fiber is larger than that of elastic fibers within CTBAD-FLW, but smaller than that of elastic fibers within Acute-A-FLW & control-FLW (Fig. 1e).
Conclusions: The FLW is stiffer in CTBAD compared to either normal or acute aortic dissection tissue due to increased collagen and decreased elastin. This change in the composition of FLW extracellular matrix may be a protective adaption to prevent aortic rupture and explains the importance of the adventitia in the surgical repair of aortic dissection.
Methods: The FLW from 14 patients (9 CTBAD and 5 Acute Type A Aortic Dissection) who underwent open aortic replacement was analyzed, and compared to iatrogenically dissected, manually peeled FLW from 6 normal transplant donor descending aortas designated as a control group (C-FLW). Biaxial tension testing in the circumferential (Circ) and axial directions was performed on the CTBAD-FLW (n=9), Acute-A-FLW (n=5) and C-FLW (n=6) tissues. Stress-strain curves were created (Fig. 1a), and a lower and higher tangent modulus (LTM & HTM) was determined for each sample to assess tissue stiffness. A histologic analysis of the tissue microstructure was performed on the collagen and elastin fibers. Quantification of the composition of collagen and elastin fibers was performed by calculating the fibers' volume fraction (VF) from Z-Stack scans (n=106 locations in 15 FLW samples [5 per group], 4-9 locations per sample based on thickness).
Results: In Circ, both LTM and HTM of CTBAD-FLW were significantly larger than those of C-FLW and Acute-A-FLW (Fig. 1b, c). In axial, HTM of the FLW was also larger than that of C-FLW and Acute-A-FLW (Fig. 1c), and LTM of Acute-A-FLW was smaller than that of C-FLW (Fig. 1b). Histology demonstrated a higher concentration of organized collagen in CTBAD-FLW compared to C-FLW and Acute-A-FLW, and a lower concentration of elastin (Fig. 1d). Quantification of the collagen/elastin profile in the tissue demonstrated a significant increase in the VF of collagen fibers and a significant decrease in the VF of elastin fibers when comparing CTBAD-FLW versus Acute-A-FLW & control-FLW (Fig. 1e). The VF of collagen fiber is larger than that of elastic fibers within CTBAD-FLW, but smaller than that of elastic fibers within Acute-A-FLW & control-FLW (Fig. 1e).
Conclusions: The FLW is stiffer in CTBAD compared to either normal or acute aortic dissection tissue due to increased collagen and decreased elastin. This change in the composition of FLW extracellular matrix may be a protective adaption to prevent aortic rupture and explains the importance of the adventitia in the surgical repair of aortic dissection.
Aortic Symposium:
Dissection
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