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Pediatric Radiology Jun 2010Although anomalies of the aortic arch and its branches are relatively uncommon malformations, they are often associated with congenital heart disease. Isolated lesions... (Review)
Review
Although anomalies of the aortic arch and its branches are relatively uncommon malformations, they are often associated with congenital heart disease. Isolated lesions may be clinically significant when the airways are compromised by a vascular ring. In this article, the development and imaging appearance of the aortic arch system and its various malformations are reviewed.
Topics: Aorta, Thoracic; Female; Heart Defects, Congenital; Humans; Infant, Newborn; Magnetic Resonance Imaging; Male; Tomography, X-Ray Computed
PubMed: 20354848
DOI: 10.1007/s00247-010-1607-9 -
Wiener Medizinische Wochenschrift (1946) May 2020Road traffic accidents are the main cause of traumatic aortic ruptures, mostly in combination with other severe injuries. The pre-hospital mortality rate is high.... (Review)
Review
Road traffic accidents are the main cause of traumatic aortic ruptures, mostly in combination with other severe injuries. The pre-hospital mortality rate is high. Suspected aortic trauma, following a high traumatic aortic injury score, is an indication for computer tomography. Injuries are triaged and the treatment priority of the aortic trauma is ascertained based on the severity of the aortic and concomitant injuries and the condition of the patient. Until definitive treatment of the aortic lesion is completed, the blood pressure of the patient must be kept low. Grade I and II lesions can be managed under strict monitoring with initial conservative treatment in individual cases. Grade III (contained perforation) and grade IV (open rupture) lesions need surgical or interventional treatment as swiftly as possible. In selected cases, a delayed treatment can also be advantageous.The endovascular stent graft therapy has established itself as the preferred form of treatment.
Topics: Aorta, Thoracic; Aortic Rupture; Blood Vessel Prosthesis Implantation; Humans; Retrospective Studies; Stents; Treatment Outcome; Wounds, Nonpenetrating
PubMed: 31858346
DOI: 10.1007/s10354-019-00727-z -
European Journal of Cardio-thoracic... Aug 2022This study aims to characterize the material properties of ascending thoracic aortic aneurysmal tissue, using regional biomechanical assessment of both tensile and...
OBJECTIVES
This study aims to characterize the material properties of ascending thoracic aortic aneurysmal tissue, using regional biomechanical assessment of both tensile and dissection propagation peel strength.
METHODS
Thirty-four aneurysm specimens (proximal thoracic aorta) were harvested en-bloc from patients undergoing surgery for aneurysm replacement. Specimens were processed into regional samples of similar shapes covering the whole aneurysm isosurface, according to a structured protocol, in both orientations (longitudinal and circumferential). Thickness mapping, uniaxial tensile and peel tests were conducted, enabling calculation of the following parameters: true stress/strain, tangential modulus, tensile strength, peeling force and dissection energy. Two constitutive material models were used (hyperelastic models of Delfino and Ogden) to fit the data. A circumferential strip of tissue was also obtained for computational histology [regional quantification of (i) elastin, (ii) collagen and (iii) smooth muscle cells].
RESULTS
The aortic wall was thinner on the outer curve (2.21, standard deviation (SD) 0.4 mm vs inner curve 2.50, SD 0.12 mm). Advanced patient age and higher pulse wave velocity (externally measured) were predictors of increased aortic wall thickness. Tensile strength was higher in the circumferential versus longitudinal direction when analysed according to anatomical regions. Both peel force (35.5, 22 N/m) and dissection energy (88.5, 69 J/m2) were on average lowest at the outer curve of the aneurysm in the longitudinal orientation. Delfino and Ogden model constants varied throughout anatomical regions, with the outer curve being associated a higher ɑ constant (Delfino) and lower µ1 constant (Ogden) (P < 0.05) indicating increased stiffness. Histologically, collagen abundance was significantly related to circumferential and longitudinal strength (P= 0.010), whilst smooth muscle cell count had no relation with any mechanical property (P > 0.05).
CONCLUSIONS
Our results suggest that the outer aortic curve is more prone to dissection propagation and perhaps less prone to rupture than the inner aortic curve. This strengthens the notion of disease heterogeneity in ascending thoracic aortic aneurysms and has implications for the pathogenesis of aortic dissection.
Topics: Aortic Dissection; Aorta, Thoracic; Aortic Aneurysm, Thoracic; Biomechanical Phenomena; Collagen; Humans; Pulse Wave Analysis; Stress, Mechanical
PubMed: 35894942
DOI: 10.1093/ejcts/ezac392 -
The Annals of Thoracic Surgery Dec 2013
Topics: Aorta, Thoracic; Aortic Aneurysm, Thoracic; Collagen; Humans; Tensile Strength
PubMed: 24296184
DOI: 10.1016/j.athoracsur.2013.07.087 -
Frontiers in Bioscience (Landmark... Jan 2012Vacuum freeze-dried blood is a good material for vascular grafts. However, studies on this technology are few, particularly on physical performance change of... (Review)
Review
Vacuum freeze-dried blood is a good material for vascular grafts. However, studies on this technology are few, particularly on physical performance change of freeze-dried blood vessel at different pre-freezing rate. In our study, pig aortas were non-invasively scanned by micro-CT in each stage of freeze-drying at different pre-freezing rates, then comparing the porosity ratio and grey level under different conditions with each other to analysis the influence of different methods on the aorta. The mechanical properties of rehydrated pig aorta and fresh one were compared by texture profile analyzer to investigate the influence of different pre-freezing rates on mechanical properties in pig aorta. Our results showed that the proper pre-freezing rate for freeze-drying were 1 C/min. The changing rates of porosity rate and the average gray scale value were 16.6% and 3.64% respectively after freeze-dried. The puncture tolerance (PT) and circumferential tensile stress were increased about 20% and 30% respectively, and the axial tensile stress (ATS) were decreased about 20% in rehydrated aorta compared with fresh aorta. We otherwise conclude that under optimized process conditions, freeze-dried aorta with proper porosity rate and mechanical properties approximate fresh aorta could be preparation.
Topics: Animals; Aorta, Thoracic; Biomechanical Phenomena; Bioprosthesis; Blood Vessel Prosthesis; Freeze Drying; In Vitro Techniques; Porosity; Tensile Strength; Tissue Preservation; Vacuum; X-Ray Microtomography
PubMed: 22201762
DOI: 10.2741/3945 -
Journal of Vascular Surgery Mar 2022
Topics: Aortic Dissection; Aorta, Thoracic; Aortic Aneurysm, Thoracic; Humans
PubMed: 35190143
DOI: 10.1016/j.jvs.2021.11.039 -
The Annals of Thoracic Surgery Nov 2012
Topics: Aorta, Thoracic; Aortic Diseases; Diverticulum; Humans; Subclavian Artery
PubMed: 23098938
DOI: 10.1016/j.athoracsur.2012.07.027 -
BMC Cardiovascular Disorders Sep 2020Effects of re-supplementation of a cholesterol-enriched diet (CEDrs) on size, cholesterol content and morphology of already existing plaques are not known to date. (Comparative Study)
Comparative Study
BACKGROUND
Effects of re-supplementation of a cholesterol-enriched diet (CEDrs) on size, cholesterol content and morphology of already existing plaques are not known to date.
METHODS
A group of rabbits received standard chow (SC) for 6 weeks ("negative control"; for plasma lipid measurements only). Group I-IV received 2% CED (induction) for 6 weeks; thereafter, groups II-IV have been fed a SC (= cholesterol withdrawal) for 68 weeks. Afterwards, feeding of groups II-IV was continued as follows: Group II - 10 weeks SC, group III - 4 weeks 0.5% CED (~re-supplementation), afterwards 6 weeks SC (~withdrawal again); group IV - 4 weeks 0.5% CED (re-supplementation) + atorvastatin (2.5 mg/kg body weight/day), afterwards 6 weeks SC (~withdrawal again) + atorvastatin. Plasma lipids, but also plaque size, morphology and cholesterol contents of thoracic aortas were quantified.
RESULTS
After CEDrs, plasma cholesterol levels were increased. However, after withdrawal of CEDrs, plasma cholesterol levels decreased, whereas the cholesterol content of the thoracic aorta was increased in comparison with the group without CEDrs. Plaque size remained unaffected. Atorvastatin application did not change plasma cholesterol level, cholesterol content of the thoracic aorta and plaque size in comparison with the group without drug treatment. However, atorvastatin treatment increased the density of macrophages (MΦ) compared with the group without treatment, with a significant correlation between densities of MΦ (Mac-1) and apoptotic (TUNEL; TP53), antigen-presenting (HLA-DR) or oxidatively stressed (SOD2) cells.
CONCLUSIONS
In rabbits with already existing plaques, CEDrs affects plaque morphology and cellular composition, but not plaque size. Despite missing effects on plasma cholesterol levels, cholesterol content of the thoracic aorta and size of already existing atherosclerotic plaques, atorvastatin treatment transforms the already existing lesions to a more active form, which may accelerate the remodelling to a more stable plaque.
Topics: Animals; Aorta, Thoracic; Aortic Diseases; Atherosclerosis; Atorvastatin; Cholesterol, Dietary; Disease Models, Animal; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Male; Plaque, Atherosclerotic; Rabbits; Time Factors
PubMed: 32942987
DOI: 10.1186/s12872-020-01703-x -
Journal of the Mechanical Behavior of... Apr 2023Collagen crosslinking, an important contributor to the stiffness of soft tissues, was found to increase with aging in the aortic wall. Here we investigated the...
Collagen crosslinking, an important contributor to the stiffness of soft tissues, was found to increase with aging in the aortic wall. Here we investigated the mechanical properties of human descending thoracic aorta with aging and the role of collagen crosslinking through a combined experimental and modeling approach. A total of 32 samples from 17 donors were collected and divided into three age groups: <40, 40-60 and > 60 years. Planar biaxial tensile tests were performed to characterize the anisotropic mechanical behavior of the aortic samples. A recently developed constitutive model incorporating collagen crosslinking into the two-fiber family model (Holzapfel and Ogden, 2020) was modified to accommodate biaxial deformation of the aorta, in which the extension and rotation kinematics of bonded fibers and crosslinks were decoupled. The mechanical testing results show that the aorta stiffens with aging with a more drastic change in the longitudinal direction, which results in altered aortic anisotropy. Our results demonstrate a good fitting capability of the constitutive model considering crosslinking for the biaxial aortic mechanics of all age groups. Furthermore, constitutive modeling results suggest an increased contribution of crosslinking and strain energy density to the biaxial stress-stretch behaviors with aging and point to excessive crosslinking as a prominent contributor to aortic stiffening.
Topics: Aging; Aorta, Thoracic; Biomechanical Phenomena; Collagen; Models, Biological; Humans; Adult; Middle Aged; Tensile Strength; Aged; Aged, 80 and over; Stress, Mechanical; Male; Female
PubMed: 36758423
DOI: 10.1016/j.jmbbm.2023.105705 -
Biomechanics and Modeling in... Feb 2020The aorta is composed of various constituents with different mechanical properties. This heterogeneous structure implies non-uniform deformation in the aorta, which...
The aorta is composed of various constituents with different mechanical properties. This heterogeneous structure implies non-uniform deformation in the aorta, which could affect local cell functions. The present study investigates 3D strains of the aorta at a cell scale induced by intraluminal pressurization. After resected mouse, thoracic aortas were stretched to their in vivo length, and the aortas were pressurized at 15, 40, 80, 120, and 160 mmHg. Images of autofluorescent light of elastin were captured under a two-photon microscope. From the movement of markers in elastic laminas (ELs) created by photo-bleaching, 3D strains (ε, ε, ε, ε, ε, ε) between two neighboring ELs in the circumferential (θ), longitudinal (z), and radial (r) directions with reference to the dimensions at 15 mmHg were calculated. The results demonstrated that the average of shear strain ε was almost 0 in a physiological pressure range (from 80 to 120 mmHg) with an absolute value |ε| changing approximately by 5%. This indicates that ELs experience radial-circumferential shear at the cell scale, but not at the whole tissue scale. The normal strains in the circumferential ε and longitudinal direction ε were positive but that in the radial direction ε was almost 0, which demonstrates that aortic tissue is not an incompressible material. The first principal direction in the radial-circumferential plane was 29° ± 13° from the circumferential direction. We show that the aorta is not simply stretched in the circumferential direction during pressurization and that cells in the aorta undergo complex deformations by nature.
Topics: Animals; Aorta, Thoracic; Elasticity; Imaging, Three-Dimensional; Mice; Muscle, Smooth; Pressure; Stress, Mechanical
PubMed: 31297645
DOI: 10.1007/s10237-019-01201-w