Background: Abdominal aortic aneurysm (AAA) rupture occurs when wall stress exceeds wall strength. Engineering principles suggest that aneurysm diameter is only one aspect of its geometry that influences wall stress. Finite element analysis considers the complete geometry and determines wall stresses throughout the structure. This article investigates the interoperator and intraoperator reliability of finite element analysis in the calculation of peak wall stress (PWS) in AAA and examines the variation in PWS in elective and acute AAAs.
Method: Full ethics and institutional approval was obtained. The study recruited 70 patients (30 acute, 40 elective) with an infrarenal AAA. Computed tomography (CT) images were obtained of the AAA from the renal vessels to the aortic bifurcation. Manual edge extraction, three-dimensional reconstruction, and blinded finite element analysis were performed to ascertain location and value of PWS. Ten CT data sets were analyzed by four different operators to ascertain interoperator reliability and by one operator twice to ascertain intraoperator reliability. An intraclass correlation coefficient was obtained. The Mann-Whitney U test and independent samples t test compared groups for statistical significance.
Results: The intraclass correlation coefficient was 0.71 for interoperator reliability and 0.84 for intraoperator reliability. There was no statistically significant difference in the mean (SD) maximal AAA diameter between elective (6.47 [1.30] cm) and acute (7.08 [1.39] cm) patients (P = .073). The difference in PWS between elective (0.67 [0.30] MPa) and acute (1.11 [0.51] MPa) patients (P = .008) was statistically significant, however.
Conclusion: Interoperator and intraoperator reliability in the derivation of PWS is acceptable. PWS, but not maximal diameter, was significantly higher in acute AAAs than in elective AAAs.
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http://dx.doi.org/10.1016/j.jvs.2007.09.002 | DOI Listing |
Acta Neuropathol
January 2025
Department of Clinical Sciences, Lund Brain Injury Laboratory for Neurosurgical Research, Lund University, 222 20, Lund, Sweden.
Traumatic brain injury (TBI) often leads to impaired regulation of cerebral blood flow, which may be caused by pathological changes of the vascular smooth muscle cells (VSMCs) in the arterial wall. Moreover, these cerebrovascular changes may contribute to the development of various neurodegenerative disorders such as Alzheimer's-like pathologies that include amyloid beta aggregation. Despite its importance, the pathophysiological mechanisms responsible for VSMC dysfunction after TBI have rarely been evaluated.
View Article and Find Full Text PDFFront Neurol
January 2025
Department of Neurology, Ajou University School of Medicine, Suwon, Republic of Korea.
Background: This study aims to investigate how A1 segment asymmetry-also known as A1 dominancy-influences the development of the anterior communicating artery aneurysm (AcomA) as it affects hemodynamic conditions within the circle of Willis (COW). Using time-of-flight magnetic resonance angiography (TOF-MRA), the research introduces a novel approach to assessing shear stress in A1 segments to uncover the hemodynamic factors contributing to AcomA formation.
Method: An observational study was conducted over 6 years at a tertiary university hospital's outpatient clinic.
Eur Heart J Case Rep
January 2025
Cardiovascular and Thoracic Division, Cardiology Department, University Hospital Southampton, Tremona Road, Southampton SO16 6YD, UK.
Background: Takotsubo cardiomyopathy usually presents with acute reversible left ventricular apical hypokinesia and apical ballooning with basal hyperdynamic function. We describe an underreported case of Takotsubo cardiomyopathy (TCM), misinterpreted as apical hypertrophic cardiomyopathy (HCM) due to transient apical oedema in the recovery phase of the condition.
Case Summary: A 74-year-old Caucasian woman, presented to the emergency department complaining of retrosternal chest pain following, emotional stress.
J Biol Phys
January 2025
The Islamia University of Bahawalpur, Bahawalpur, Pakistan.
The present article focuses on the analysis of the two-phase flow of blood via a stenosed artery under the influence of a pulsatile pressure gradient. The core and plasma regions of flow are modeled using the constitutive relations of Herschel-Bulkley and the Newtonian fluids, respectively. The problem is modeled in a cylindrical coordinate system.
View Article and Find Full Text PDFSci Rep
January 2025
School of Engineering, The University of Manchester, Manchester, UK.
This study examines how heart rate (HR) affects hemodynamics in a South African infant with Coarctation of the Aorta. Computed tomography angiography segments aortic coarctation anatomy; Doppler echocardiography derives inlet flow waveforms. Simulations occur at 100, 120, and 160 beats per minute, representing reduced, resting, and elevated HR levels.
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