Proximal aortic aneurysms: correlation of maximum aortic diameter and aortic wall thickness

Abstract OBJECTIVES The goal of therapy of proximal aortic aneurysms is to prevent an aortic catastrophe, e.g. acute dissection or rupture. The decision to intervene is currently based on maximum aortic diameter complemented by known risk factors like bicuspid aortic valve, positive family history or rapid growth rate. When applying Laplace’s law, wall tension is determined by pressure × radius divided by aortic wall thickness. Because current imaging modalities lack precision, wall thickness is currently neglected. The purpose of our study was therefore to correlate maximum aortic diameter with aortic wall thickness and known indices for adverse aortic events. METHODS Aortic samples from 292 patients were collected during cardiac surgery, of whom 158 presented with a bicuspid aortic valve and 134, with a tricuspid aortic valve. Aortic specimens were obtained during the operation and stored in 4% formaldehyde. Histological staining and analysis were performed to determine the thickness of the aortic wall. RESULTS Patients were 62 ± 13 years old at the time of the operation; 77% were men. The mean aortic dimensions were 44 mm, 41 mm and 51 mm at the aortic root, sinotubular junction and ascending aorta, respectively. Aortic valve stenosis was the most frequent (49%) valvular dysfunction, followed by aortic valve regurgitation (33%) and combined dysfunction (10%). The maximum aortic diameter at the ascending level did not correlate with the thickness of the media (R = 0.07) or the intima (R = 0.28) at the convex sample site. There was also no correlation of the ascending aortic diameter with age (R = −0.18) or body surface area (R = 0.07). The thickness of the intima (r = 0.31) and the media (R = 0.035) did not correlate with the Svensson index of aortic risk. Similarly, there was a low (R = 0.29) or absent (R = −0.04) correlation between the aortic size index and the intima or media thickness, respectively. There was a similar relationship of median thickness of the intima in the 4 aortic height index risk categories (P < 0.001). CONCLUSIONS Aortic diameter and conventional indices of aortic risk do not correlate with aortic wall thickness. Other indices may be required in order to identify patients at high risk for aortic complications.

Download Full-text

Abstract 102: Granular Media Calcinosis in the Aortic Wall of Patients With Bicuspid and Tricuspid Aortic Valves

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.34.suppl_1.102 ◽

2014 ◽

Vol 34 (suppl_1) ◽

Author(s):

Sandy von Salisch ◽

Josephina Haunschild ◽

Martin Misfeld ◽

Michael A Borger ◽

Stefan Dhein ◽

...

Keyword(s):

Aortic Valve ◽

Bicuspid Aortic Valve ◽

Granular Media ◽

Aortic Wall ◽

Aortic Disease ◽

Dissecting Aneurysm ◽

Media Thickness ◽

Significant Difference ◽

The Media ◽

Aneurysm Dissection

Background: Bicuspid aortic valve is the most frequent congenital cardiac abnormality and associated with proximal aortic disease (i.e. aneurysm, dissection or rupture). Granular media calcinosis(GMC)--suggested to increase stiffness and play a pathogenetic role in dissecting aneurysm--has not yet been quantified in BAV. Methods: Specimen of the proximal aortic wall from 76 patients--32 with tricuspid (TAV) and 44 with bicuspid aortic valve (BAV)--were obtained during surgery to quantify media thickness and GMC by von Kossa staining (panel C), comparing the convexity (Cvx) and concavity (Ccv) in BAV vs. TAV. Results: Interlamellar GMC affected the most central layers of the media and those adjacent to the outer adventitia with a doubling within both--the Cvx and Ccv--of pts with BAV compared to patients with TAV (13.3±9.6 vs. 6.6±7.4 and 12.8±10.8 vs. 6.4±7.1; p<0.05, panel A) was seen, but neither a difference in calcification between the Ccx and the Ccv side within the BAV nor the TAV group. No association between age and calcification grade , neither in the Cvx nor the Ccv (r=0.132, p=0.218 and 0.103, p=0.341) was seen. There was a significant difference in the total media thickness between BAV and TAV at the Cvx (867±162μm vs . 993±158μm; p<0.05) and the Ccv (1005 ± 236 vs 1223 ± 217μm; p<0.05, panel B). Independent of aortic valve morphology, the Cvx was thinner than the Ccv side (TAV: 993 ± 158 vs.1223 ± 217μm; p<0.001; BAV: 869 ± 162 vs.1005 ± 236μm; p<0.05, panel B). Conclusion: BAVs had significantly thinner media and twice as much GMC than their tricuspid peers possibly associated with the loosening of the bond between the elastic lamellae causing a decrease in elasticity possibly explaining a higher risk for dissection and rupture.

Download Full-text

Identification of Aorta-Specific DNA Methylation Patterns in Cell-Free DNA from Patients with Bicuspid Aortic Valve-Associated Aortopathy and Correlation with Aortic Wall Cell Death

10.1101/2020.12.20.423686 ◽

2020 ◽

Author(s):

Ashna Maredia ◽

David Guzzardi ◽

Mohammad Aleinati ◽

Fatima Iqbal ◽

Aiswarya Madhu ◽

...

Keyword(s):

Cell Death ◽

Aortic Valve ◽

Bicuspid Aortic Valve ◽

Aortic Wall ◽

Aortic Diameter ◽

Tunel Staining ◽

Chromosome 11 ◽

Cell Free Dna ◽

Free Dna ◽

Wall Cell

ABSTRACTObjectiveIn a proof-of-concept study we sought to identify aorta-specific differentially methylated regions (DMRs) detectable in plasma cell-free DNA (cfDNA) obtained from patients with bicuspid aortic valve (BAV)-associated aortopathy.MethodsWe used bioinformatics and publicly-available human methylomes to identify aorta-specific DMRs. We used data from 4D-flow cardiac magnetic resonance imaging to identify regions of elevated aortic wall shear stress (WSS) in patients with BAV-associated aortopathy undergoing surgery and correlated WSS regions with aortic tissue cell death assessed using TUNEL staining. Cell-free DNA was isolated from patient plasma and levels of candidate DMRs were correlated with aortic diameter and aortic wall cell death.ResultsAortic wall cell death was not associated with maximal aortic diameter but was significantly associated with elevated WSS. We identified 24 candidate aorta-specific DMRs and selected 4 for further study. A DMR on chromosome 11 showed acceptable specificity for the aorta and correlated significantly with aortic wall cell death. Plasma levels of total and aorta-specific cfDNA did not correlate with aortic diameter.ConclusionsElevated WSS created by abnormal flow hemodynamics is associated with increased aortic wall cell death which supports the use of aorta-specific cfDNA as a potential tool to identify aortopathy and stratify patient risk.Date and Number of Institutional Review Board ApprovalREB17-0207

Download Full-text

Weak Relationship of Intraperitoneal Fat Volume With Ascending Aortic Wall Thickness

Obesity ◽

10.1038/oby.2011.368 ◽

2012 ◽

Vol 20 (6) ◽

pp. 1136-1137

Author(s):

Larry E. Miller

Keyword(s):

Wall Thickness ◽

Aortic Wall ◽

Weak Relationship ◽

Aortic Wall Thickness ◽

Relationship Of ◽

Fat Volume

Download Full-text

Matrix Metalloproteinase-2 Isoforms Differ within the Aortic Wall of Ascending Aortic Aneurysms Associated with Bicuspid Aortic Valve

Cardiology Research and Practice ◽

10.1155/2020/1306425 ◽

2020 ◽

Vol 2020 ◽

pp. 1-9

Author(s):

Ramona Schmitt ◽

Anke Tscheuschler ◽

Philipp Laschinski ◽

Philipp Discher ◽

Jana Fuchs ◽

...

Keyword(s):

Aortic Valve ◽

Matrix Metalloproteinase ◽

Bicuspid Aortic Valve ◽

Aortic Wall ◽

Aortic Aneurysms ◽

Matrix Metalloproteinase 2 ◽

Enzyme Linked Immunosorbent Assay ◽

Tissue Levels ◽

Protein Levels ◽

Underlying Pathogenesis

The pathogenesis of ascending thoracic aortic aneurysm (aTAA) is thought to differ between patients with bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV), and one of the causes is different hemodynamics. Influenced by hemodynamics, the tissue levels of proteins associated with aTAA might differ between aTAAs with BAV and TAV and between different localities within the aortic wall. We therefore analyzed aTAA tissue levels of MMP-2 (matrix metalloproteinase-2) isoforms (Pro-MMP-2, active MMP-2, and total MMP-2) and tissue levels of MMP-14, TIMP-2 (tissue inhibitor of metalloproteinase-2), MMP-9, and TIMP-1 in 19 patients with BAV and 23 patients with TAV via gelatin zymography and enzyme-linked immunosorbent assay (ELISA), respectively. TAV and BAV groups’ protein levels did not differ significantly. Whereas the TAV group exhibited no significant differences in protein levels between the aneurysm’s anterior and posterior parts, the BAV group revealed significantly higher levels of Pro-MMP-2, total MMP-2, and TIMP-2 in the aneurysm’s posterior parts (mean Pro-MMP-2 200.52 arbitrary units (AU) versus 161.12 AU, p=0.007; mean total MMP-2 235.22 AU versus 193.68 AU, p=0.002; mean TIMP-2 26.90 ng/ml versus 25.36 ng/ml, p=0.009), whereas the other proteins did not differ significantly within the aortic wall. Thus, MMPs are distributed more heterogeneously within the aortic wall of aTAAs associated with BAV than in those associated with TAV, which is a new aspect for understanding the underlying pathogenesis. This heterogeneous protein level distribution might be attributable to differences in the underlying pathogenesis, especially hemodynamics. This result is important for further studies as it will be essential to specify the location of samples to ensure data comparability regarding the main goals of understanding the pathogenesis of aTAA, optimizing treatments, and establishing a screening method for its potentially deadly complications.

Download Full-text

Abstract 107: Increased Peak Wall Stress in Women With Abdominal Aortic Aneurysms

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.37.suppl_1.107 ◽

2017 ◽

Vol 37 (suppl_1) ◽

Author(s):

Eric Shang ◽

Grace Wang ◽

Ronald Fairman ◽

Benjamin Jackson

Keyword(s):

Wall Thickness ◽

Aortic Wall ◽

Wall Stress ◽

Aortic Aneurysms ◽

Patient Specific ◽

Rupture Risk ◽

Intraluminal Thrombus ◽

Abdominal Aortic ◽

Aortic Wall Thickness ◽

Peak Wall Stress

Objective: Women with abdominal aortic aneurysms (AAA) exhibit more rapid aneurysm growth and greater rupture risk at equivalent diameters relative to men. Evidence suggests that biomechanical peak wall stress (PWS) derived from finite element analysis of AAAs is a superior predictor of rupture compared to maximum transverse diameter (MTD). This study aimed to investigate differences in the calculated PWS of AAAs between men and women. Method: Men (n=35) and women (n=35) with infrarenal AAAs with 45-55mm MTD undergoing CTA were identified. Customized image processing algorithms extracted patient-specific AAA geometries from raw DICOM images. The resulting aortic reconstructions incorporated patient-specific and regionally resolved aortic wall thickness, intraluminal thrombus, and wall calcifications. Aortic models were loaded with 120mmHg blood pressure using commercially available FEA solvers. Results: Peak wall stress was found to be significantly higher in women (299±51 vs 257±53 kPA, P=0.001, see Figure). Neither MTD (50.5±3.1 vs 49.8±2.9 mm, P=0.34), mean aortic wall thickness (2.38±0.52 vs 2.34±0.50 mm, P=0.69), nor wall thickness at location of PWS (2.36±0.60 vs 2.20±0.46 mm, P=0.20) varied by sex. While there were no sex-associated differences in aneurysm volume (86.6±27.0 vs 94.8±25.5 cm 3 , P=0.76) or intraluminal thrombus volume (14.2±11.7 vs 16.3±13.4 mm, P=0.33), women’s AAAs had significantly increased maximum Gaussian curvature (0.032±0.011 vs 0.025±0.015 mm -2 , P=0.03). Conclusion: Comparably sized AAAs in women were shown to have significantly higher peak wall stress. Maximum gaussian curvature, a measure of aneurysm morphology, was significantly different between the two groups. These results suggest that men and women possess distinct aneurysm geometries, and that PWS-derived rupture risk prediction may provide a more reliable estimator of rupture risk in all patients.

Download Full-text

Prediction of Progression or Regression of Type A Aortic Intramural Hematoma by Computed Tomography

Circulation ◽

10.1161/circ.100.suppl_2.ii-281 ◽

1999 ◽

Vol 100 (suppl_2) ◽

Author(s):

Shuichiro Kaji ◽

Kazuhiro Nishigami ◽

Takashi Akasaka ◽

Takeshi Hozumi ◽

Tsutomu Takagi ◽

...

Keyword(s):

Computed Tomography ◽

Wall Thickness ◽

Aortic Wall ◽

Intramural Hematoma ◽

Type A ◽

Ct Images ◽

Aortic Diameter ◽

Aortic Wall Thickness ◽

Aortic Intramural Hematoma

Background —It has been reported that early surgery should be required for patients with type A aortic intramural hematoma (IMH) because it tends to develop classic aortic dissection or rupture. However, the anatomic features of type A IMH that develops dissection or rupture are unknown. The purpose of this study was to investigate the predictors of progression or regression of type A IMH by computed tomography (CT). Methods and Results —Twenty-two consecutive patients with type A IMH were studied by serial CT images. Aortic diameter and aortic wall thickness of the ascending aorta were estimated in CT images at 3 levels on admission and at follow-up (mean 37 days). We defined patients who showed increased maximum aortic wall thickness in the follow-up CT (n=9) or died of rupture (n=1) as the progression group (n=10). The other 12 patients, who all showed decreased maximum wall thickness, were categorized as the regression group. In the progression group, the maximum aortic diameter in the initial CT was significantly greater than that in the regression group (55±6 vs 47±3 mm, P =0.001). A Cox regression analysis revealed that the maximum aortic diameter was the strongest predictor for progression of type A IMH. We considered the optimal cutoff value to be 50 mm for the maximum aortic diameter to predict progression (positive predictive value 83%, negative predictive value 100%). Conclusions —Maximum aortic diameter estimated by the initial CT images is predictive for progression of type A IMH.

Download Full-text

Aorta-specific DNA methylation patterns in cell-free DNA from patients with bicuspid aortic valve-associated aortopathy

Clinical Epigenetics ◽

10.1186/s13148-021-01137-y ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Ashna Maredia ◽

David Guzzardi ◽

Mohammad Aleinati ◽

Fatima Iqbal ◽

Arshroop Khaira ◽

...

Keyword(s):

Cell Death ◽

Aortic Valve ◽

Bicuspid Aortic Valve ◽

Aortic Wall ◽

Aortic Diameter ◽

Prophylactic Surgery ◽

Chromosome 11 ◽

Cell Free Dna ◽

Free Dna ◽

Wall Cell

Abstract Background The dilation of the aorta that occurs as a consequence of a congenitally bicuspid aortic valve (BAV) is associated with a risk of dissection, aneurysm or rupture. With progressive aortopathy, surgery is often recommended, but current patient selection strategies have limitations. A blood-based assay to identify those who would most benefit from prophylactic surgery would be an important medical advance. In a proof-of-concept study, we sought to identify aorta-specific differentially methylated regions (DMRs) detectable in plasma cell-free DNA (cfDNA) obtained from patients undergoing surgery for BAV-associated aortopathy. Methods We used bioinformatics and publicly available human methylomes to identify aorta-specific DMRs. We used data from 4D-flow cardiac magnetic resonance imaging to identify regions of elevated aortic wall shear stress (WSS) in patients with BAV-associated aortopathy undergoing surgery and correlated WSS regions with aortic tissue cell death assessed using TUNEL staining. Cell-free DNA was isolated from patient plasma, and levels of candidate DMRs were correlated with aortic diameter and aortic wall cell death. Results Aortic wall cell death was not associated with maximal aortic diameter but was significantly associated with elevated WSS. We identified 24 candidate aorta-specific DMRs and selected 4 for further study. A DMR on chromosome 11 was specific for the aorta and correlated significantly with aortic wall cell death. Plasma levels of total and aorta-specific cfDNA did not correlate with aortic diameter. Conclusions In a cohort of patients undergoing surgery for BAV-associated aortopathy, elevated WSS created by abnormal flow hemodynamics was associated with increased aortic wall cell death which supports the use of aorta-specific cfDNA as a potential tool to identify aortopathy and stratify patient risk.

Download Full-text

AB0967 Determinants of Aortic Wall Thickness in Patients without Aortitis: A Computed Tomography-Based Study: Table 1

Annals of the Rheumatic Diseases ◽

10.1136/annrheumdis-2014-eular.1116 ◽

2014 ◽

Vol 73 (Suppl 2) ◽

pp. 1119.3-1120

Author(s):

A. Nakhleh ◽

D. Rimar ◽

I. Rukhkyan ◽

V. Wolfson ◽

I. Rosner ◽

...

Keyword(s):

Computed Tomography ◽

Wall Thickness ◽

Aortic Wall ◽

Aortic Wall Thickness

Download Full-text

Bicuspid aortic valve morphology and aortic valvular outflow jets: an experimental analysis using an MRI-compatible pulsatile flow circulation system

Scientific Reports ◽

10.1038/s41598-021-81845-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Kaoru Hattori ◽

Natsuki Nakama ◽

Jumpei Takada ◽

Gohki Nishimura ◽

Ryo Moriwaki ◽

...

Keyword(s):

Aortic Valve ◽

Bicuspid Aortic Valve ◽

Pulsatile Flow ◽

Aortic Wall ◽

Ascending Aorta ◽

Circulation System ◽

Resonance Imaging ◽

Left Posterior ◽

Flow Circulation ◽

The Right

AbstractThe characteristics of aortic valvular outflow jet affect aortopathy in the bicuspid aortic valve (BAV). This study aimed to elucidate the effects of BAV morphology on the aortic valvular outflow jets. Morphotype-specific valve-devising apparatuses were developed to create aortic valve models. A magnetic resonance imaging-compatible pulsatile flow circulation system was developed to quantify the outflow jet. The eccentricity and circulation values of the peak systolic jet were compared among tricuspid aortic valve (TAV), three asymmetric BAVs, and two symmetric BAVs. The results showed mean aortic flow and leakage did not differ among the five BAVs (six samples, each). Asymmetric BAVs demonstrated the eccentric outflow jets directed to the aortic wall facing the smaller leaflets. In the asymmetric BAV with the smaller leaflet facing the right-anterior, left-posterior, and left-anterior quadrants of the aorta, the outflow jets exclusively impinged on the outer curvature of the ascending aorta, proximal arch, and the supra-valvular aortic wall, respectively. Symmetric BAVs demonstrated mildly eccentric outflow jets that did not impinge on the aortic wall. The circulation values at peak systole increased in asymmetric BAVs. The bicuspid symmetry and the position of smaller leaflet were determinant factors of the characteristics of aortic valvular outflow jet.

Download Full-text