Demonstration of circumferential heterogeneity in displacement and strain in the abdominal aortic wall by spiral cine DENSE MRI

2018 ◽  
Vol 49 (3) ◽  
pp. 731-743 ◽  
Author(s):  
Elizabeth Iffrig ◽  
John S. Wilson ◽  
Xiadong Zhong ◽  
John N. Oshinski
Keyword(s):  
Aortic Wall ◽  
Abdominal Aortic ◽  
Cine Dense

scholarly journals Initial Clinical Experience With a New Conformable Abdominal Aortic Endograft: Aortic Neck Coverage and Curvature Analysis in Challenging Aortic Necks

2021 ◽  
pp. 152660282199672
Author(s):  
Alice Finotello ◽  
Richte Schuurmann ◽  
Sara Di Gregorio ◽  
Gian Antonio Boschetti ◽  
Nabil Chakfé ◽  
...  
Keyword(s):  
Aortic Wall ◽  
Surface Coverage ◽  
Infrarenal Aorta ◽  
Technical Success ◽  
Curvature Analysis ◽  
Average Curvature ◽  
Aortic Neck ◽  
Abdominal Aortic ◽  
Shortest Distance ◽  
New Generation

Objectives: Aim of this work was to investigate precision of deployment and conformability of a new generation GORE EXCLUDER Conformable Endoprosthesis with active control system (CEXC Device, W.L. Gore and Associates, Flagstaff, AZ, USA) by analyzing aortic neck coverage and curvature. Methods: All consecutive elective patients affected by abdominal aortic aneurysm or aortoiliac aneurysm treated at our institution between November 2018 and June 2019 with the new CEXC Device were enrolled. Validated software was adopted to determine the available apposition surface area into the aortic neck, apposition of the endograft to the aortic wall, shortest apposition length (SAL), shortest distance between the endograft fabric and the lowest renal arteries (SFD) and between the endograft fabric and the contralateral renal artery (CFD). Pointwise centerline curvature was also computed. Results: Twelve patients (10 men, median age 78 years (71.75, 81.0)) with available pre- and postoperative computed tomography angiography (CTA) were included. Technical success was obtained in all the cases. Preoperative median length of the proximal aortic neck was 16.1 mm (10.7, 21.7) and suprarenal (α) and infrarenal (β) neck angulation were, respectively, 28.9° (15.7°, 47.5°) and 75.0° (66.9°, 81.4°). Postoperative median apposition surface coverage was 79% (69.25%, 90.75%) of the available apposition surface. SFD and CFD were 1.5 mm (0.75, 5.25) and 7 mm (4.5, 21.5), respectively. Average curvature over the infrarenal aorta decreased from 25 m−1 (21.75, 29.0) to 22.5 m−1 (18.75, 24.5) postoperatively (p=0.02). Maximum curvature did not decrease significantly from 64.5 m−1 (54.25, 92.0) to 62 m−1 (41.75, 71.5) (p=0.1). Conclusions: Our early experience showed that deployment of the CEXC Device is safe and effective for patients with challenging proximal aortic necks. Absence of significant changes between pre- and postoperative proximal aortic neck angulations and curvature confirms the high conformability of this endograft.

scholarly journals ASSOCIATION OF ABDOMINAL AORTIC WALL INFLAMMATION, HEPATIC FLUORODEOXYGLUCOSE UPTAKE AND VISCERAL ADIPOSE TISSUE BIOLOGICAL ACTIVITY IN PATIENTS WITH DYSLIPIDEMIAS

2017 ◽  
Vol 69 (11) ◽  
pp. 1436
Author(s):  
Koutagiar Peter Iosif ◽  
Konstantinos Toutouzas ◽  
Georgios Benetos ◽  
Nikoletta Piannou ◽  
Alexios Antonopoulos ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Biological Activity ◽  
Visceral Adipose Tissue ◽  
Aortic Wall ◽  
Abdominal Aortic ◽  
Visceral Adipose

A Novel Noninvasive Technique for Pulse-Wave Imaging and Characterization of Clinically-Significant Vascular Mechanical Properties In Vivo

2007 ◽  
Vol 29 (3) ◽  
pp. 137-154 ◽  
Author(s):  
Kana Fujikura ◽  
Jianwen Luo ◽  
Viktor Gamarnik ◽  
Mathieu Pernot ◽  
Royd Fukumoto ◽  
...  
Keyword(s):  
Aortic Wall ◽  
Pulse Wave ◽  
Distal Region ◽  
Noninvasive Technique ◽  
Abdominal Aortic ◽  
Wave Imaging ◽  
Risk Patients ◽  
Noninvasive Mapping ◽  
Clinically Significant

The pulse-wave velocity (PWV) has been used as an indicator of vascular stiffness, which can be an early predictor of cardiovascular mortality. A noninvasive, easily applicable method for detecting the regional pulse wave (PW) may contribute as a future modality for risk assessment. The purpose of this study was to demonstrate the feasibility and reproducibility of PW imaging (PWI) during propagation along the abdominal aortic wall by acquiring electrocardiography-gated (ECG-gated) radiofrequency (rf) signals noninvasively. An abdominal aortic aneurysm (AAA) was induced using a CaCl2 model in order to investigate the utility of this novel method for detecting disease. The abdominal aortas of twelve normal and five CaCl2, mice were scanned at 30 MHz and electrocardiography (ECG) was acquired simultaneously. The radial wall velocities were mapped with 8000 frames/s. Propagation of the PW was demonstrated in a color-coded ciné-loop format in all cases. In the normal mice, the wave propagated in linear fashion from a proximal to a distal region. However, in CaCl2 mice, multiple waves were initiated from several regions (i.e., most likely initiated from various calcified regions within the aortic wall). The regional PWV in normal aortas was 2.70 ± 0.54 m/s ( r2 = 0.85 ± 0.06, n = 12), which was in agreement with previous reports using conventional techniques. Although there was no statistical difference in the regional PWV between the normal and CaCl2-treated aortas (2.95 ± 0.90 m/s ( r2 = 0.51 ± 0.22, n = 5)), the correlation coefficient was found to be significantly lower in the CaCl2-treated aortas ( p<0.01). This state-of-the-art technique allows noninvasive mapping of vascular disease in vivo. In future clinical applications, it may contribute to the detection of early stages of cardiovascular disease, which may decrease mortality among high-risk patients.

Abstract 297: Segmental Aortic Stiffening is a Mechanism Driving Early Abdominal Aortic Aneurysm Pathogenesis

2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Uwe Raaz ◽  
Alexander M Zöllner ◽  
Ryuji Toh ◽  
Futoshi Nakagami ◽  
Isabel N Schellinger ◽  
...  
Keyword(s):  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Aortic Wall ◽  
Ex Vivo ◽  
Wall Stress ◽  
Finite Elements Analysis ◽  
External Application ◽  
Abdominal Aortic ◽  
Aneurysm Growth ◽  
Aortic Stiffening

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.

scholarly journals In Vivo Quantification of Regional Circumferential Green Strain in the Thoracic and Abdominal Aorta by Two-Dimensional Spiral Cine DENSE MRI

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
John S. Wilson ◽  
Xiaodong Zhong ◽  
Jackson Hair ◽  
W. Robert Taylor ◽  
John N. Oshinski
Keyword(s):  
Abdominal Aorta ◽  
Aortic Wall ◽  
Patient Specific ◽  
Peak Strain ◽  
Ssfp Cine ◽  
Green Strain ◽  
The Mean ◽  
Thoracic And Abdominal ◽  
Cine Dense

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.

scholarly journals The relationship between aortic wall distensibility and rupture of infrarenal abdominal aortic aneurysm

2003 ◽  
Vol 37 (1) ◽  
pp. 112-117 ◽  
Author(s):  
Katie A. Wilson ◽  
Amanda J. Lee ◽  
Amanda J. Lee ◽  
Peter R. Hoskins ◽  
F.Gerry R. Fowkes ◽  
...  
Keyword(s):  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Aortic Wall ◽  
Infrarenal Abdominal Aortic Aneurysm ◽  
Abdominal Aortic ◽  
The Relationship ◽  
Wall Distensibility

Material Properties of Abdominal Aortic Aneurysm Wall From Uniaxial Tests

2000 ◽  
Author(s):  
Mano J. Thubrikar ◽  
Michel Labrosse ◽  
Jihad Al-Soudi ◽  
Brett Fowler ◽  
Francis Robicsek
Keyword(s):  
Experimental Data ◽  
Material Properties ◽  
Aortic Wall ◽  
Abdominal Aortic Aneurysms ◽  
Aortic Aneurysms ◽  
Modeling Tools ◽  
Aneurysm Wall ◽  
Abdominal Aortic ◽  
Abdominal Aortic Aneurysm Wall ◽  
Mechanical Models

Abstract Abdominal aortic aneurysms (AAA) rupture when the aortic wall cannot withstand the stresses and strains induced by the pulsatile blood pressure. In recent years, different mechanical models of aneurysms have been presented (Vorp et al., 1998, Di Martino et al., 1998, Thubrikar et al., 1999). Although powerful modeling tools such as finite elements are available, there is still a need for experimental data concerning the mechanical properties of the aneurysm wall.

Abstract 667: The Role of Aortic Wall-Nuclear Factor- kappa B (NF-kB) Signaling in Formation of Dissecting Aortic Aneurysms

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Talha Ijaz ◽  
Hong Sun ◽  
Adrian Recinos ◽  
Ronald G Tilton ◽  
Allan R Brasier
Keyword(s):  
Flow Cytometry ◽  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Aortic Wall ◽  
Aortic Rupture ◽  
Aortic Aneurysms ◽  
Tunel Staining ◽  
Abdominal Aortic ◽  
Significant Difference

Introduction: Abdominal aortic aneurysm is a devastating disease since it can lead to aortic rupture and instantaneous death. We previously demonstrated that IL-6 secreted from the aortic wall is necessary for the development of abdominal aortic aneurysm and dissection (AAD). Since IL-6 is a NF-kB/RelA dependant gene, we investigated the role of aortic wall- NF-kB/RelA signaling in the development of AAD. Methods and Results: To test the role of aortic wall-RelA, we utilized Cre-Lox technology to delete RelA from aortic cells. Tamoxifen-inducible, Col1a2-promoter driven Cre mice (Col1a2-Cre) were crossed with mT/mG Cre-reporter mice to determine which aortic cells undergo genetic recombination after Cre activation. Flow cytometry analysis of the aortic wall indicated that 88% of the genetically recombined cells were SMCs and 8% were fibroblasts. Next, RelA floxed (RelA f/f) mice, generated in our lab, were crossed with Col1a2-Cre mice. RelA f/f Cre+ and RelA f/f Cre- were stimulated with tamoxifen for 10 days to generate aortic-RelA deficient (Ao-RelA-/-) or wild-type (Ao-RelA+/+) transgenics. Flow cytometry, qRT-PCR, and immunohistochemistry analysis suggested a depletion of aortic-RelA greater than 60%. To test the role of Ao-RelA in AAD, Ao-RelA -/- (n= 20) and Ao-RelA +/+ (n=14) mice were infused with angiotensin II for 7 days. Surprisingly, 20% of Ao-RelA-/- mice died from development of AAD and aortic rupture while no deaths were observed in Ao-RelA+/+ group. In addition, 40% of Ao-RelA-/- mice developed AAD compared to 14% of Ao-RelA+/+ mice. There was no significant difference in TUNEL staining or ERTR7+ fibroblast population between the two groups. Conclusion: Our studies suggest that aortic wall-RelA may be necessary for protection from AAD.

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