scholarly journals Defining a master curve of abdominal aortic aneurysm growth and its potential utility of clinical management

2020 ◽  
Author(s):  
Emrah Akkoyun ◽  
Hamidreza Gharahi ◽  
Sebastian T. Kwon ◽  
Byron A. Zambrano ◽  
Akshay Rao ◽  
...  
Keyword(s):  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Growth Model ◽  
Master Curve ◽  
Clinical Decision Making ◽  
Least Square ◽  
Maximum Diameter ◽  
Morphological Parameters ◽  
Abdominal Aortic ◽  
Spherical Diameter

AbstractObjectiveThe maximum diameter measurement of an abdominal aortic aneurysm (AAA), which depends on orthogonal and axial cross-sections or maximally inscribed spheres within the AAA, plays a significant role in the clinical decision making process. This study aims to build a large dataset of morphological parameters from longitudinal CT scans and analyze their correlations. Furthermore, this work explores the existence of a “master curve” of AAA growth, and tests which parameters serve to enhance its predictability for clinical use.Methods106 CT scan images from 25 Korean AAA patients were retrospectively obtained. We subsequently computed morphological parameters, growth rates, and pair-wise correlations, and attempted to enhance the predictability of the growth for high-risk aneurysms using non-linear curve fitting and least-square minimization.ResultsAn exponential AAA growth model was fitted to the maximum spherical diameter, as the best representative of the growth among all parameters (r-square: 0.985) and correctly predicted to 74 of 79 scans based on a 95% confidence interval. AAA volume expansion rateswere highly correlated (r=0.80) with thrombus accumulation rates.ConclusionsThe exponential growth model using spherical diameter provides useful information about progression of aneurysm size and enables AAA growth rate extrapolation during a given surveillance period.

scholarly journals Maximum Diameter of Native Abdominal Aortic Aneurysm Measured by Angio-Computed Tomography

Aorta ◽  
2015 ◽  
Vol 03 (02) ◽  
pp. 47-55 ◽  
Author(s):  
Caroline Mora ◽  
Claude Marcus ◽  
Coralie Barbe ◽  
Fiona Ecarnot ◽  
Anne Long
Keyword(s):  
Computed Tomography ◽  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Weighted Kappa ◽  
Maximum Diameter ◽  
Clinical Decisions ◽  
Diameter Measurement ◽  
Double Blind ◽  
Automated Method ◽  
Abdominal Aortic

Background: Computed tomography angiography (CTA) is the reference technique for the measurement of native maximum abdominal aortic aneurysm (AAA) diameter when surgery is being considered. However, there is a wide choice available for the methodology of maximum AAA diameter measurement on CTA, and to date, no consensus has been reached on which method is best. We analyzed clinical decisions based on these various measures of native maximum AAA diameter with CTA, then analyzed their reproducibility and identified the method of measurement yielding the highest agreement in terms of patient management. Materials and Methods: Three sets of measures in 46 native AAA were obtained, double-blind by three radiologists (J, S, V) on orthogonal planes, curved multiplanar reconstructions, and semi-automated-software, based on the AAA-lumen centerline. From each set, the clinical decision was recorded as follows: "Follow-up" (if all diameters <50 mm), "ambiguous" (if at least one diameter <50 mm AND at least one ≥50 mm) or "Surgery " (if all diameters ≥50 mm). Intra- and interobserver agreements in clinical decisions were compared using the weighted Kappa coefficient. Results: Clinical decisions varied according to the measurement sets used by each observer, and according to intra and interobserver (lecture#1) reproducibility. Based on the first reading of each observer, the number of AAA proposed for surgery ranged from 11 to 24 for J, 5 to 20 for S, and 15 to 23 for V. The rate of AAAs classified as "ambiguous" varied from 11% (5/46) to 37% (17/46).The semi-automated method yielded very good intraand interobserver agreements in clinical decisions in all comparisons (Kappa range 0.83–1.00). Conclusion: The semi-automated method seems to be appropriate for native AAA maximum diameter measurement on CTA. In the absence of AAA outer-wallbased software more robust for complex AAA, clinical decisions might best be made with diameter values obtained using this technique.

The similarities and differences among patients with abdominal aortic aneurysms referred to a tertiary hospital and found at necropsy

Vascular ◽  
2014 ◽  
Vol 23 (4) ◽  
pp. 411-418 ◽  
Author(s):  
Erasmo S da Silva ◽  
Vitor C Gornati ◽  
Ivan B Casella ◽  
Ricardo Aun ◽  
Andre EV Estenssoro ◽  
...  
Keyword(s):  
Risk Factors ◽  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Protective Factor ◽  
Abdominal Aortic Aneurysms ◽  
Aortic Aneurysms ◽  
Maximum Diameter ◽  
Transverse Diameter ◽  
Abdominal Aortic ◽  
Tertiary Center

Objective To analyze the characteristics of patients with abdominal aortic aneurysms referred to a tertiary center and to compare with individuals with abdominal aortic aneurysm found at necropsy. Methods We have retrospectively analyzed the medical records of 556 patients with abdominal aortic aneurysm and 102 cases abdominal aortic aneurysm found at necropsy. Results At univariated analysis, hypertension, tobacco use and maximum diameter were significant risk factors for symptomatic aneurysm, while diabetes tended to be a protective factor for rupture. By logistic regression analysis, the largest transverse diameter was the only one significantly associated with abdominal aortic aneurysm rupture ( p < .0001, odds ratio 1.7, 95% confidence interval 1.481–1.951). Intact abdominal aortic aneurysm found at necropsy showed similarities with outpatients in relation to abdominal aortic aneurysm diameter and risk factors. Conclusion Intact abdominal aortic aneurysm at necropsy and at outpatients setting showed similarities that confirmed that abdominal aortic aneurysm repair is less offered to women, and they died more frequently with intact abdominal aortic aneurysm from other causes.

A Methodology for Verifying Abdominal Aortic Aneurysm Wall Stress

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Sergio Ruiz de Galarreta ◽  
Aitor Cazón ◽  
Raúl Antón ◽  
Ender A. Finol
Keyword(s):  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Experimental Testing ◽  
Wall Stress ◽  
Intraluminal Pressure ◽  
Maximum Diameter ◽  
Numerical Studies ◽  
Aneurysm Wall ◽  
Abdominal Aortic ◽  
Geometric Factors

An abdominal aortic aneurysm (AAA) is a permanent focal dilatation of the abdominal aorta of at least 1.5 times its normal diameter. Although the criterion of maximum diameter is still used in clinical practice to decide on a timely intervention, numerical studies have demonstrated the importance of other geometric factors. However, the major drawback of numerical studies is that they must be validated experimentally before clinical implementation. This work presents a new methodology to verify wall stress predicted from the numerical studies against the experimental testing. To this end, four AAA phantoms were manufactured using vacuum casting. The geometry of each phantom was subject to microcomputed tomography (μCT) scanning at zero and three other intraluminal pressures: 80, 100, and 120 mm Hg. A zero-pressure geometry algorithm was used to calculate the wall stress in the phantom, while the numerical wall stress was calculated with a finite-element analysis (FEA) solver based on the actual zero-pressure geometry subjected to 80, 100, and 120 mm Hg intraluminal pressure loading. Results demonstrate the moderate accuracy of this methodology with small relative differences in the average wall stress (1.14%). Additionally, the contribution of geometric factors to the wall stress distribution was statistically analyzed for the four phantoms. The results showed a significant correlation between wall thickness and mean curvature (MC) with wall stress.

Assessment of Abdominal Aortic Aneurysm Risk: Asymmetry as an Additional Diagnostic Tool?

2008 ◽  
Author(s):  
Barry J. Doyle ◽  
Anthony Callanan ◽  
Michael T. Walsh ◽  
David A. Vorp ◽  
Timothy M. McGloughlin
Keyword(s):  
Risk Factors ◽  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Surgical Intervention ◽  
Current Trend ◽  
Wall Stress ◽  
Posterior Wall ◽  
Maximum Diameter ◽  
Infrarenal Aorta ◽  
Abdominal Aortic

An abdominal aortic aneurysm (AAA) can be defined as a permanent and irreversible localised dilation of the infrarenal aorta. This localised dilation is a result of a degradation of the elastic media of the arterial wall. This degradation of the aortic wall can be attributed to risk factors such as tobacco smoking, sex, age, hypertension, chronic obstructive pulmonary disease, hyperlipidaemia, and family history of the disorder [1]. With the recent advancements in medicine, more AAAs are being detected than ever. Approximately 500,000 new cases are diagnosed each year worldwide resulting in 15,000 deaths per year in the USA alone [2]. Currently, the rupture risk of AAAs is regarded as a continuous function of aneurysm size, with surgical intervention decided based on the maximum diameter of the AAA. Most AAA repairs are performed when the diameter exceeds 50–60mm. It has been shown that maximum diameter may not be a reliable predictor of rupture, as smaller AAAs can also rupture. It is believed by many researchers that there is a need to review the determination of the timing of surgical intervention based solely on aneurysm diameter, and include other relevant risk factors. These additional risk factors could, for example, include, AAA wall stress, AAA expansion rate, degree of asymmetry, presence of intraluminal thrombus (ILT), and hypertension. The addition of these parameters may aid the surgical decision-making process. Shifting the current trend towards more encompassing assessment of AAA rupture potential may help reduce the morbidity and mortality rates associated with AAA repair. It was previously reported [3] that 82% of AAA ruptures occur on the posterior wall. In this research, the asymmetry of the AAA is examined, with respect to both peak wall stress and posterior wall stress, in ten realistic cases, and a resulting threshold factor is presented.

Spatial Distribution of Abdominal Aortic Aneurysm Surface Expansion and Correlation With Maximum Diameter and Volume Growth

2019 ◽  
Vol 58 ◽  
pp. 276-288
Author(s):  
Konstantinos Tzirakis ◽  
Nikolaos Kontopodis ◽  
Eleni Metaxa ◽  
Christos V. Ioannou ◽  
Yannis Papaharilaou
Keyword(s):  
Spatial Distribution ◽  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Volume Growth ◽  
Maximum Diameter ◽  
Abdominal Aortic ◽  
Surface Expansion

Abstract 15501: Repeated Social Defeat Exaggerates Cacl2-induced Abdominal Aortic Aneurysm Expansion by Suppression of Periaortic Fibrosis in Tissue Repair Phase

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Hiroshi Kubota ◽  
Hiroyuki Yamada ◽  
Takeshi Sugimoto ◽  
Daisuke Miyawaki ◽  
Noriyuki Wakana ◽  
...  
Keyword(s):  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Inflammatory Response ◽  
Social Defeat ◽  
Physical Contact ◽  
Maximum Diameter ◽  
Elastic Membrane ◽  
Infrarenal Aorta ◽  
Abdominal Aortic ◽  
External Elastic Membrane

Background and Objective: Depression is an independent risk factor of cardiovascular disease and significantly associated with the prevalence of abdominal aortic aneurysm (AAA). We investigated the impact of repeated social defeat (RSD) on AAA formation. Methods and Results: Eight-week-old male WT mice were exposed to RSD by housing with a larger CD-1 mouse in a shared cage. They were subjected to vigorous physical contact daily for 10 consecutive days. Control mice were housed in the same cage without physical contact. After social interaction test to confirm depressive-like behaviors, mice underwent application of 0.5M calcium chloride (CaCl 2 ) on the infrarenal aorta. At one-week, maximum diameter and circumference of external elastic membrane were comparable between the two groups. The number of F-4/80 and MMP-9-positive cells in immunofluorescent images were also comparable. Consistently, fluorescent image taken by IVIS revealed no difference in MMP activity, suggesting that acute inflammatory response was comparable between the two groups. In contrast, at two weeks, maximum diameter and circumference of external elastic membrane were significantly increased in defeated mice ( p < 0.01). Intriguingly, periaortic fibrotic area in aneurysmal portion was markedly decreased in defeated mice (12.5х10 3 μm 2 vs. 3.7х10 3 μm 2 , Control vs. Defeat, p < 0.01). Consistently, accumulation of α-SMA-positive cells in adventitia of aneurysmal portion was much lesser in defeated mice (876 cells/mm 2 vs. 319 cells/mm 2 , Control vs. Defeat, p < 0.05), whereas those in tunica media of non-aneurysmal portion did not show any difference between the two groups. LPS-induced iNOS gene and protein expressions in bone marrow-derived macrophages (BMDMs) were significantly decreased in defeated mice, whereas the TGF-β-induced phosphorylation of Smad2 and ERK1/2 in primary cultured aortic VSMCs were comparable between the two groups. Conclusions: Our findings demonstrate that RSD enhances AAA expansion by suppressing the periaortic fibrosis following inflammatory response, and suggest that decreased NO production from accumulated macrophages contributes to the reduced VSMCs proliferation and collagen deposition.

Platelet activation after endovascular repair of abdominal aortic aneurysm

Vascular ◽  
2015 ◽  
Vol 24 (3) ◽  
pp. 287-294 ◽  
Author(s):  
Eleni Arnaoutoglou ◽  
George Kouvelos ◽  
Nektario Papa ◽  
Achilleas Karamoutsios ◽  
Vasilios Bouris ◽  
...  
Keyword(s):  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Endovascular Aneurysm Repair ◽  
High Sensitivity ◽  
Maximum Diameter ◽  
Maximum Temperature ◽  
Abdominal Aortic ◽  
Significant Difference ◽  
Hs Crp ◽  
Wbc Count

Aim To investigate the effect of endovascular aneurysm repair (EVAR) on platelet (PLT) function and reveal possible associated factors. Methods Fifty consecutive patients were included. PLT count and activation (CD62P-CD36), white blood cell (WBC) count, and high sensitivity C-reactive protein (hs-CRP) were measured preoperatively, at the first and third postoperative day. Results EVAR elicited a significant reduction in PLT count from baseline to first day after EVAR ( p < 0.001), while no significant difference was noted between the first and third day. Furthermore, CD62P expression was markedly elevated at the first day after EVAR (median % positive PLTs from 13.7 at baseline to 22.1, p = 0.05), but returned to baseline levels by the third day. Maximum abdominal aortic aneurysm diameter was the only factor that significantly affected the CD62P values ( p = 0.005). Postoperative CD36 values were significantly correlated with total aneurysm volume ( p = 0.05) and were higher in endografts made from polyester ( p = 0.01). There were no correlation between PLT activation and hs-CRP, WBC, maximum temperature, and 30-day morbidity. Conclusion EVAR has elucidated a significant reduction in PLT count and increase in PLT activation at the immediate postoperative period. The type of the endograft material and the aneurysm maximum diameter and volume appear to play an important role in PLT activation.

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