Layer-Specific Distributed Collagen Fiber Orientations in Human Arteries, From Thoracic Aorta to Common Iliac

Author(s):  
Andreas J. Schriefl ◽  
Peter Regitnig ◽  
David M. Pierce ◽  
Gerhard A. Holzapfel

We use the well established method of polarized microscopy on picrosirius red stained tissue samples and a dispersion model to quantify over 37000 measured layer-specific 3D fiber orientations of 11 human thoracic and abdominal aortas and common iliac arteries. Our results yield mean fiber directions, quantitative dispersion data and the existence of two distinct and prominent fiber families for all layers of the aortic wall.

2011 ◽  
Vol 9 (71) ◽  
pp. 1275-1286 ◽  
Author(s):  
Andreas J. Schriefl ◽  
Georg Zeindlinger ◽  
David M. Pierce ◽  
Peter Regitnig ◽  
Gerhard A. Holzapfel

The established method of polarized microscopy in combination with a universal stage is used to determine the layer-specific distributed collagen fibre orientations in 11 human non-atherosclerotic thoracic and abdominal aortas and common iliac arteries (63 ± 15.3 years, mean ± s.d.). A dispersion model is used to quantify over 37 000 recorded fibre angles from tissue samples. The study resulted in distinct fibre families, fibre directions, dispersion and thickness data for each layer and all vessels investigated. Two fibre families were present for the intima, media and adventitia in the aortas, with often a third and sometimes a fourth family in the intima in the respective axial and circumferential directions. In all aortas, the two families were almost symmetrically arranged with respect to the cylinder axis, closer to the axial direction in the adventitia, closer to the circumferential direction in the media and in between in the intima. The same trend was found for the intima and adventitia of the common iliac arteries; however, there was only one preferred fibre alignment present in the media. In all locations and layers, the observed fibre orientations were always in the tangential plane of the walls, with no radial components and very small dispersion through the wall thickness. A wider range of in-plane fibre orientations was present in the intima than in the media and adventitia. The mean total wall thickness for the aortas and the common iliac artery was 1.39 and 1.05 mm, respectively. For the aortas, a slight thickening of the intima and a thinning of the media in increasingly distal regions were observed. A clear intimal thickening was present distal to the branching of the celiac arteries. All data, except for the media of the common iliac arteries, showed two prominent collagen fibre families for all layers so that two-fibre family models seem most appropriate.


2015 ◽  
Vol 78 (8) ◽  
pp. 723-730 ◽  
Author(s):  
André Nazac ◽  
Stéphane Bancelin ◽  
Benjamin Teig ◽  
Bicher Haj Ibrahim ◽  
Hervé Fernandez ◽  
...  

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
John S. Wilson ◽  
Xiaodong Zhong ◽  
Jackson Hair ◽  
W. Robert Taylor ◽  
John N. Oshinski

Regional tissue mechanics play a fundamental role in the patient-specific function and remodeling of the cardiovascular system. Nevertheless, regional in vivo assessments of aortic kinematics remain lacking due to the challenge of imaging the thin aortic wall. Herein, we present a novel application of displacement encoding with stimulated echoes (DENSE) magnetic resonance imaging (MRI) to quantify the regional displacement and circumferential Green strain of the thoracic and abdominal aorta. Two-dimensional (2D) spiral cine DENSE and steady-state free procession (SSFP) cine images were acquired at 3T at either the infrarenal abdominal aorta (IAA), descending thoracic aorta (DTA), or distal aortic arch (DAA) in a pilot study of six healthy volunteers (22–59 y.o., 4 females). DENSE data were processed with multiple custom noise reduction techniques including time-smoothing, displacement vector smoothing, sectorized spatial smoothing, and reference point averaging to calculate circumferential Green strain across 16 equispaced sectors around the aorta. Each volunteer was scanned twice to evaluate interstudy repeatability. Circumferential Green strain was heterogeneously distributed in all volunteers and locations. The mean spatial heterogeneity index (standard deviation of all sector values divided by the mean strain) was 0.37 in the IAA, 0.28 in the DTA, and 0.59 in the DAA. Mean (homogenized) peak strain by DENSE for each cross section was consistent with the homogenized linearized strain estimated from SSFP cine. The mean difference in peak strain across all sectors following repeat imaging was −0.1±2.3%, with a mean absolute difference of 1.7%. Aortic cine DENSE MRI is a viable noninvasive technique for quantifying heterogeneous regional aortic wall strain and has significant potential to improve patient-specific clinical assessments of numerous aortopathies, as well as to provide the lacking spatiotemporal data required to refine patient-specific computational models of aortic growth and remodeling.


Author(s):  
Dalma CSIBI ◽  
Adrian Florin GAL ◽  
Cristian RATIU ◽  
Viorel MICLAUS

In blood vessels situated just after the heart, an irregular blood flow occurs due to some specific structural elements of the tunica media. The current paper describes the histological aspects of some post-cardiac arterial sections in lamb. The tissue samples were collected from five 30 days old male lambs (Țurcană breed). Histological specimens from different regions of the aorta were harvested (i.e., the ascending aorta, aortic arch, thoracic and abdominal regions of the descending aorta). From the specified regions, small pieces (cca. 0.5 cm) were fixed in neutral 10% buffered formalin. The tissues were subsequently embedded in paraffin wax, sectioned at 5 μm, and stained with Goldner’s trichrome and Verhoeff methods. Tissue analysis was performed using an Olympus system for image acquisition and analysis. Histological appearance of the assessed segments of the aorta in lamb is unusual. Major changes occur in tunica media of the aorta. In the ascending aorta, aortic arch and thoracic regions of the aorta, the histological outline is somewhat the same. The internal region of the media possesses the typical lamellar arrangement. Concerning the outer part of tunica media, the smooth muscle has a tendency to form bundles of various sizes. The muscle islands are not present in the media of abdominal region of the aorta, which exhibits the classic pattern of elastic arteries.


2016 ◽  
Vol 21 (7) ◽  
pp. 071111 ◽  
Author(s):  
Dmitry D. Yakovlev ◽  
Marina E. Shvachkina ◽  
Maria M. Sherman ◽  
Andrey V. Spivak ◽  
Alexander B. Pravdin ◽  
...  

Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Carla S Ceron ◽  
Elen Rizzi ◽  
Danielle A Guimaraes ◽  
Alisson Martins-Oliveira ◽  
Raquel F Gerlach ◽  
...  

Nebivolol and metoprolol are β1-adrenergic receptor blockers with different properties. We hypothesized that nebivolol, but not metoprolol, could attenuate prooxidant and profibrotic mechanisms of hypertension vascular remodeling. Hypertension was induced in male Wistar rats by clipping the left renal artery. Six weeks after surgery, hypertensive and sham rats were treated with nebivolol (Nebi 10 mg/kg/day), metoprolol (Meto 20 mg/kg/day) or vehicle for four weeks. Systolic blood pressure was monitored weekly. Morphologic changes in the aortic wall were studied in picrosirius red sections. Aortic NAD(P)H activity was evaluated by luminescence. Nitrotyrosine staining was evaluated to assess peroxynitrite formation by immunohistochemistry. TGF-β and matrix metalloproteinase-9 (MMP-9) levels were determined by immunofluorescence, and p-ERK 1/2 expression by western blotting. Both β1-receptor antagonists exerted very similar antihypertensive effects (156 ± 8 mmHg and 151 ± 9 mmHg, respectively, versus 206 ± 7 mmHg in hypertensive controls; both P<0.05). However, while metoprolol had no significant effects, nebivolol significantly (all P<0.05) attenuated vascular collagen surface (237944 ± 59567, 69784 ± 17686, 183215 ± 30338 μm2, respectively, in the 2K1C, 2K1C+Nebi, and 2K1C+Meto groups), attenuated hypertension-induced increases in aortic NAD(P)H oxidase activity (253887 ± 13712, 143765 ± 15642, and 232465 ± 14352 AU, respectively in the 2K1C, 2K1C+Nebi, and 2K1C+Meto groups), in nitrotyrosine levels (166.3 ± 2.9, 145.3 ± 1.5, 172.1 ± 7.3 AU, respectively, in the 2K1C, 2K1C+Nebi, and 2K1C+Meto groups), in TGF-β upregulation (7.2 ± 0.12, 6.5 ± 0.03, 7.0 ± 0.3 AU, respectively, in the 2K1C, 2K1C+Nebi, and 2K1C+Meto groups) and in MMP-9 levels (18.27 ± 0.8, 12.73 ± 0.4, 15.76 ± 1.4 AU, respectively in the 2K1C, 2K1C+Nebi, and 2K1C+Meto groups). No effects on p-ERK 1/2 expression were found with both drugs (P>0.05) (1.0 ± 0.16, 0.92 ± 0.15, 0.87 ± 0.37 AU, respectively, in the 2K1C, 2K1C+Nebi, and 2K1C+Meto groups). These results show for the first time that nebivolol, but not metoprolol, attenuates prooxidant and profibrotic mechanisms involving TGF-β and MMP-9, which promote vascular remodeling in hypertension.


2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Ida Maria Hjelm Sørensen ◽  
Sasha Asbøll Kepler Saurbrey ◽  
Henrik Øder Hjortkjær ◽  
Philip Brainin ◽  
Nicholas Carlson ◽  
...  

Abstract Background Patients with chronic kidney disease (CKD) and arterial calcification are considered at increased risk of adverse cardiovascular outcomes. However, the optimal site for measurement of arterial calcification has not been determined. The primary aim of this study was to examine the pattern of arterial calcification in different stages of CKD. Methods This was an observational, cross-sectional study that included 580 individuals with CKD stages 1–5 (no dialysis) from the Copenhagen CKD Cohort. Calcification of the carotid, coronary and iliac arteries, thoracic and abdominal aorta was assessed using non-contrast multidetector computed tomography scans and quantified according to the Agatston method. Based on the distribution of Agatston scores in the selected arterial region, the subjects were divided into calcium score categories of 0 (no calcification), 1–100, 101–400 and > 400. Results Participants with CKD stages 3–5 had the highest prevalence of calcification and the highest frequency of calcium scores > 400 in all arterial sites. Calcification in at least one arterial site was present in > 90% of patients with CKD stage 3. In all five CKD stages prevalence of calcification was greatest in both the thoracic and abdominal aorta, and in the iliac arteries. These arterial sites also showed the highest calcium scores. High calcium scores (> 400) in all five arterial regions were independently associated with prevalent cardiovascular disease. In multivariable analyses, after adjusting for cardiovascular risk factors, declining creatinine clearance was associated with increasing calcification of the coronary arteries (p = 0.012) and the thoracic aorta (p = 0.037) only. Conclusions Arterial calcification is highly prevalent throughout all five CKD stages and is most prominent in both the thoracic and abdominal aorta, and in the iliac arteries. Follow-up studies are needed to explore the potential of extracardiac calcification sites in prediction of cardiovascular events in the CKD population.


2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
T M Matajira Chia ◽  
M Castineira Busto ◽  
M Cespon Fernandez ◽  
B Gimena Reyes ◽  
F Calvo Iglesias ◽  
...  

Abstract A 61-year-old man was admitted to the hospital with an atypical pain lumbar with oligoanuria. Other comorbidities were: arterial hypertension, diabetes mellitus and smoking .On examination the patient was comfortable at rest, with a heart rate of 89 b.p.m. and a blood pressure of 147/2 mmHg. Normal S1 and S2 heart sounds were present. There were no signs of heart failure present. Patients complained of pain in hypogastrium on palpation. Creatinine 2.33 mg / dL. PCR 72. The immunological studies were normal (including IgG and IgA serological levels, antinuclear antibodies, extractable nuclear antigens, anti-neutrophil cytoplasmic antibodies. An Body CT was performed, it shows mass that includes the ureters as well as the iliac arteries and parietal thickening in aorta wall. The positron emission tomography–computed tomography (PET CT) scans was performed that evidences pathological hypermetabolism that surrounds both primitive iliac arteries with maximum SUV 12 g / ml. Pathological hypermetabolism in ascending aorta until reaching arch with maximum SUV of 9.1 mg / ml compatible with periaortitis in the ascending aorta. A study was completed with retroperitoneal mass biopsy that showed areas of retroperitoneal fibrosis with predominantly lymphoplasmacytic areas. IgG4 / IgG&gt; 40% , Obliterative involvement of small venules suggestive of IgG4 disease. A transthoracic echocardiogram was performed which showed normal biventricular function, absence of significant valvular disease and thickening of the aortic wall compatible with periaortitis. The patient started glucocorticoid therapy with favorable response. A PET CT control was performed that showed disappearing retroperitoneal masses around iliac vessels and disappearance of activity in lateral wall of aorta and decrease activity about ascendent aorta. DIAGNOSIS : IgG4 -related aortitis Abstract P273 Figure.


Vascular ◽  
2020 ◽  
pp. 170853812092784
Author(s):  
Michele Antonello ◽  
Francesco Squizzato ◽  
Michele Piazza

Introduction The covered endovascular reconstruction of the aortic bifurcation (CERAB) represents a promising technique for the treatment obstructive lesions involving the aortic bifurcation. The aim of this report is to describe the use of a new generation balloon-expandable stent-graft (Viabahn VBX, W.L. Gore&Associates, AZ, USA), in the CERAB configuration for the treatment of aorto-iliac obstructive lesions involving the infrarenal aorta and bifurcation. Technical note: This technique was adopted in two patients with severe aorto-iliac obstructive lesions. After bilateral iliac recanalization, an 11 mm diameter VBX stent was deployed in the infrarenal aorta; a post-dilatation up to 16 mm with a non-compliant balloon was performed to adapt the proximal edge of the stent to the aortic diameter. Two 8 mm diameter VBX stents were then deployed at the aortic bifurcation in a kissing conformation, overlapping with the previously positioned aortic stent for 15 mm. A post-ballooning with two kissing 12 × 20 mm compliant balloons (Powerflex Pro PTA, Cordis, CA, USA) was performed to adapt the parallel stents to the aortic cuff. A post-operative angio-CT demonstrated optimal conformability of the aortic cuff to the aortic wall, and apposition of the kissing stents to the aortic cuff. Conclusions This preliminary experience shows that the VBX stent may allow an effective reconstruction of the aortic bifurcation; the conformability and flaring capability may allow to overcome the diameter mismatch between the aorta and the iliac arteries.


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