On the severity of aortic stenosis in ascending aortic aneurysm: A computational tool to examine ventricular-arterial interaction and aortic wall stress

Stiffening of the aortic wall is a phenomenon consistently observed in abdominal aortic aneurysm (AAA). However, its role in AAA pathophysiology is largely undefined. Using an established murine elastase-induced AAA model, we demonstrate that segmental aortic stiffening (SAS) precedes aneurysm growth. Finite elements analysis (FEA)-based wall stress calculations reveal that early stiffening of the aneurysm-prone aortic segment leads to axial (longitudinal) stress generated by cyclic (systolic) tethering of adjacent, more compliant wall segments. Interventional stiffening of AAA-adjacent segments (via external application of surgical adhesive) significantly reduces aneurysm growth. These changes correlate with reduced segmental stiffness of the AAA-prone aorta (due to equalized stiffness in adjacent aortic segments), reduced axial wall stress, decreased production of reactive oxygen species (ROS), attenuated elastin breakdown, and decreased expression of inflammatory cytokines and macrophage infiltration, as well as attenuated apoptosis within the aortic wall. Cyclic pressurization of stiffened aortic segments ex vivo increases the expression of genes related to inflammation and extracellular matrix (ECM) remodeling. Finally, human ultrasound studies reveal that aging, a significant AAA risk factor, is accompanied by segmental infrarenal aortic stiffening. The present study introduces the novel concept of segmental aortic stiffening (SAS) as an early pathomechanism generating aortic wall stress and thereby triggering AAA growth. Therefore monitoring SAS by ultrasound might help to better identify patients at risk for AAA disease and better predict the susceptibility of small AAA to further growth. Moreover our results suggest that interventional mechanical stiffening of the AAA-adjacent aorta may be further tested as a novel treatment option to limit early AAA growth.

Download Full-text

Assessment of wall stress distribution in thoracic ascending aortic aneurysm: Simulation, prediction, and prevention

Journal of Thoracic and Cardiovascular Surgery ◽

10.1016/j.jtcvs.2020.04.178 ◽

2020 ◽

Vol 160 (3) ◽

pp. e101 ◽

Cited By ~ 3

Author(s):

Wenrui Ma ◽

Yulin Liang ◽

Chunsheng Wang

Keyword(s):

Aortic Aneurysm ◽

Stress Distribution ◽

Wall Stress ◽

Ascending Aortic Aneurysm ◽

Prediction And Prevention

Download Full-text

REDUCED AORTIC WALL STRESS IN DIABETES MELLITUS - A CONTRIBUTOR FOR THE LOW INCIDENCE OF ABDOMINAL AORTIC ANEURYSM?

Journal of Hypertension ◽

10.1097/00004872-200406002-00686 ◽

2004 ◽

Vol 22 (Suppl. 2) ◽

pp. S197-S198

Author(s):

H. Åstrand ◽

Å.R. Ahlgren ◽

G. Sundkvist ◽

T. Länne

Keyword(s):

Diabetes Mellitus ◽

Abdominal Aortic Aneurysm ◽

Aortic Aneurysm ◽

Aortic Wall ◽

Wall Stress ◽

Abdominal Aortic ◽

Low Incidence

Download Full-text

Aortic wall thickness in patients with ascending aortic aneurysm versus acute aortic dissection

European Journal of Cardio-Thoracic Surgery ◽

10.1093/ejcts/ezv197 ◽

2015 ◽

Vol 49 (3) ◽

pp. 756-762 ◽

Cited By ~ 7

Author(s):

Joeri Van Puyvelde ◽

Eric Verbeken ◽

Peter Verbrugghe ◽

Paul Herijgers ◽

Bart Meuris

Keyword(s):

Aortic Aneurysm ◽

Aortic Dissection ◽

Wall Thickness ◽

Aortic Wall ◽

Acute Aortic Dissection ◽

Ascending Aortic Aneurysm ◽

Aortic Wall Thickness

Download Full-text

Engineering Analysis of Aortic Wall Stress in the Surgery of V-shape Resection of the Noncoronary Sinus

10.1101/2020.12.02.20239475 ◽

2020 ◽

Author(s):

Hai Dong ◽

Minliang Liu ◽

Tongran Qin ◽

Liang Liang ◽

Bulat Ziganshin ◽

...

Keyword(s):

Aortic Aneurysm ◽

Stress Field ◽

Aortic Arch ◽

Aortic Root ◽

Wall Stress ◽

Aortic Aneurysms ◽

Patient Specific ◽

Rupture Risk ◽

Ascending Aortic Aneurysm ◽

Post Surgery

AbstractAscending aortic aneurysms often include the sinotubular junction (STJ) and extend into the root portion of the aorta. The novel surgery of the V-shape resection of the noncoronary sinus of the aortic root has been shown to be a simpler procedure, comparing with traditional surgeries such as full aortic root replacement, for patients with moderate ascending aortic aneurysm and aortic root ectasia. This novel surgery could reduce the diameter and cross-sectional area of the aortic root. However, the detailed effect on the stress field and the rupture risk of the aortic root and aneurysm has not been fully investigated. In this study, we performed patient-specific finite element (FE) analysis based on the 3D geometries of the aortic root and ascending aortic aneurysm, reconstructed directly from the clinical computed tomographic (CT) images. By comparing the pre- and post-surgery results, we investigated the influence of the V-shape surgery on the stress field and rupture risk of the aortic root, ascending aortic aneurysm and aortic arch. It was found that the surgery could significantly reduce the wall stress of the aortic root, ascending aortic aneurysm, as well the aortic arch, and hence lower the rupture risk.

Download Full-text

Fibromuscular dysplasia of aortic aneurysm vasa vasorum (a rare case report)

Kuban Scientific Medical Bulletin ◽

10.25207/1608-6228-2020-27-4-169-178 ◽

2020 ◽

Vol 27 (4) ◽

pp. 169-178

Author(s):

S. S. Todorov ◽

V. Yu. Deribas ◽

A. S. Kaz’min ◽

S. S. Todorov

Keyword(s):

Aortic Aneurysm ◽

Histological Examination ◽

Fibromuscular Dysplasia ◽

Aortic Wall ◽

Vasa Vasorum ◽

Wall Thickening ◽

Elastic Fibres ◽

Ascending Aortic Aneurysm ◽

Aneurysm Wall ◽

Smooth Myocytes

Aim. To describe a rare occurrence of ﬁbromuscular vasa vasorum dysplasia of the aortic aneurysm wall.Materials and methods. Surgical material from the ascending aortic aneurysm wall was examined. Longitudinal strips of the aortic wall were excised for histological examination with subsequent 24-h ﬁxation in 10% buffered formalin. A histological isopropanol assay was performed with an automated Logos microwave tissue processor (Milestone, Italy) with subsequent sample embedding into parafﬁn. Sections were obtained with a rotary microtome (Leica, Germany). Staining was performed with haematoxylin-eosin, van Gieson’s picrofuchsin, orcein for elastic ﬁbres, Hotchkiss’ PAS reaction with alcian blue for glycosaminoglycans. Histological and histochemical properties of the aortic wall were studied and imaged with a Leica DM 1000 microscope (Germany) equipped with a camera ICC50 E at magniﬁcations 40x, 100x, 200x, 400x.Results. The conducted histological examination of the aortic aneurysm wall revealed most pronounced changes in media and adventitia layers. Elastic ﬁbres in media were swollen, homogeneous, crimped, with pronounced dystrophic and necrobiotic changes in smooth myocytes. Regions of compromised cells and elastic ﬁbres in media contained pockets of alcian-positive glycosaminoglycans. Speciﬁc changes were revealed in adventitia vasa vasorum in the form of a pronounced wall thickening and lumen narrowing due to dysplastic ﬁbromuscular tissues.Conclusion. A rare form of ﬁbromuscular dysplasia of the vasa vasorum of the ascending aortic aneurysm wall observed in a 43 years-old woman demonstrated the morbid morphology of smooth myocytes, as well as ﬁbrous collagenous and elastic structures. The described features were likely associated with the aortic wall trophic structure and aneurysm morphogenesis.

Download Full-text

Evaluation of Distensibility and Stiffness of Ascending Aortic Aneurysm using Magnetic Resonance Imaging

Journal of Nepal Medical Association ◽

10.31729/jnma.2852 ◽

2016 ◽

Vol 55 (204) ◽

pp. 67-71

Author(s):

Kaushal Kishore Tiwari ◽

Stefano Bevilacqua ◽

Giovanni Aquaro ◽

Pierluigi Festa ◽

Lamia Ait-Ali ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Aortic Aneurysm ◽

Pulse Wave Velocity ◽

Wave Velocity ◽

Aortic Wall ◽

Pulse Wave ◽

Ascending Aorta ◽

Resonance Imaging ◽

Ascending Aortic Aneurysm

Introduction: Magnetic resonance imaging emerging as a new tool for the diagnosis and evaluation of ascending aortic aneurysm. The aim of our study is to evaluate in vivo distensibility and pulse wave velocity of the aortic wall using functional magnetic resonance imaging technique.Methods: We enrolled 25 patients undergoing surgery for ascending aortic aneurysm and or aortic valve replacement for a period of 8 months. Preoperatively, all the patients underwent functional MRI study of the aorta. Aortic wall distensibility and pulse wave velocity of ascending aorta was evaluated. Results: Mean age of the patient was 66 years (66.68 ± 5.62 years) with 60% (15) male patients. More than fifty percentages of patients were smoker (52%), hypertensive (64%) and diabetic (56%). We have observed significant decrease of distensibilty in the patients with aortic diameter above 50 mm (p-0.0002). Furthermore, we have found a significant inverse correlation between aortic distensibility and pulse wave velocity (R= -0.650, R2= 0.42, p-0.0004). Similarly, we have found a significant inverse correlation between ascending aortic diameter and distensibility of the aorta (R= -0.785, R2= 0.61, p-0.00001). Statistically significant positive correlation was observed between aortic diameter and pulse wave velocity (R= 0.865, R2= 0.74, p-0.00001).Conclusions: MRI measurement of aortic diameters, distensibility, and flow wave velocity is an easy, reliable and reproducible technique. Distensibility and pulse wave velocity define the elasticity of the aorta. We have observed that elasticity of aortic wall is decreased in ascending aorta aneurysm patients. Keywords: ascending aorta aneurysm; distensibility; pulse wave velocity; MRI. | PubMed

Download Full-text