Search results for "aorta"
showing 10 items of 458 documents
Computer Modeling for the Prediction of Thoracic Aortic Stent Graft Collapse
2011
OBJECTIVE: To assess the biomechanical implications of excessive stent protrusion into the aortic arch in relation to thoracic aortic stent graft (TASG) collapse by simulating the structural load and quantifying the fluid dynamics on the TASG wall protrusion extended into a model arch. METHODS: One-way coupled fluid-solid interaction analyses were performed to investigate the flow-induced hemodynamic and structural loads exerted on the proximal protrusion of the TASG and aortic wall reconstructed from a patient who underwent traumatic thoracic aortic injury repair. Mechanical properties of a Gore TAG thoracic endoprosthesis (W. L. Gore and Assoc, Flagstaff, Ariz) were assessed via experimen…
Anatomical anomalies and variations of main thoracic vessels in dogs: a computed tomography study.
2019
Abstract Introduction There is scarce information about the prevalence of anomalies and anatomical variations of the main great thoracic vessels in dogs, particularly in dogs without congenital heart disease. Animals The study included 878 privately owned dogs. Material and methods Computerized tomography (CT) thoracic studies carried out between 2011 and 2014 for a variety of reasons were reviewed. The prevalence of anomalies and anatomical variations of the aorta and vena cava, the arterial branches of the aortic arch and the main branches of the intrathoracic veins in dogs with no evidence of congenital heart disease was evaluated. Poor-quality CTs, CTs with thoracic pathology that impai…
Total occlusion of aortic arch in a 62-year-old man presenting with acute myocardial infarction
2011
Not available
An In Vitro Phantom Study on the Role of the Bird-Beak Configuration in Endograft Infolding in the Aortic Arch.
2015
Purpose: To assess endograft infolding for excessive bird-beak configurations in the aortic arch in relation to hemodynamic variables by quantifying device displacement and rotation of oversized stent-grafts deployed in a phantom model. Methods: A patient-specific, compliant, phantom pulsatile flow model was reconstructed from a patient who presented with collapse of a Gore TAG thoracic endoprosthesis. Device infolding was measured under different flow and pressure conditions for 3 protrusion extensions (13, 19, and 24 mm) of the bird-beak configuration resulting from 2 TAG endografts with oversizing of 11% and 45%, respectively. Results: The bird-beak configuration with the greatest protr…
Gadolinium-DTPA (Magnevist®) als Kontrastmittel für die arterielle DSA
1994
16 DSA investigations using intra-arterial Gd-DTPA were performed on 12 patients. The contrast medium was administered either as a 0.5 molar gadolinium solution (commercially available) or diluted with distilled water to a 0.2-0.4 molar gadolinium solution. The injection was made either by pressure injector or by hand. The aortic arch, abdominal aorta and pelvic and lower limb arteries were examined. 14 of the 16 procedures were diagnostically adequate, but compared with iodinated contrast materials, contrast was less marked. There were no cardiovascular, neurological or allergic side effects. Three patients suffered a feeling of heat and one patient had mild pain during the injection. Even…
David V procedure with concomitant ascending aorta, aortic arch and descending aorta replacement in adult patient with coarctation of aorta
2021
Framework for Fluid-Structure Interaction Analysis of Aortic Coarctation Resulting From Proximal Protusion of Thoracic Aortic Stent Graft Into the Ar…
2011
Thoracic aortic stent grafts (TASG) are commonly used to repair aortic anomalies or diseases in a minimally-invasive fashion. One complication of TASG is collapse, whereby blood is unable to completely flow through the graft as intended. Most TASG collapses occur in the setting of endovascular repair of traumatic thoracic aortic transection, where a typically smaller diameter aorta of pediatric patients is repaired with a relatively larger diameter endograft designed to treat aneurysmal disease [1]. It is hypothesized that the poor apposition of the leading edge of the proximal stent graft to the lesser curvature of the aortic arch can result increased hemodynamic force at the leading side …
Reference values of fetal aortic flow velocity waveforms and associated intra-observer reliability in normal pregnancies
2001
Objectives It was the aim of the present study to calculate new Doppler reference ranges for blood flow velocities (Vmax, Vmean, Vmin) and resistance indices (PI, RI) for the fetal descending aorta by automatic waveform analysis. Design Cross-sectional prospective study. Subjects Nine hundred and twenty-six low-risk pregnancies at 18–41 weeks' gestation. Methods Aortic blood flow velocities were derived with pulsed-wave color Doppler. Measurements were carried out at the level of the diaphragm. Reference ranges for the individual measuring parameters were constructed based on a growth function from a four-parameter class of monotonic continuous functions according to the smallest square pri…
Assessment of Thoracic Aortic Dimensions in an Experimental Setting: Comparison of Different Unenhanced Magnetic Resonance Angiography Techniques Wit…
2008
PURPOSE To compare different unenhanced magnetic resonance angiography (MRA) techniques for quantitative evaluation of vessel lumen in an experimental setting in young pigs whose dimensions allow for a comparison with a pediatric population. MATERIAL AND METHODS Magnetic resonance imaging was performed in 5 healthy ventilated pigs at 1.5 T. Three different electrocardiogram (ECG)-triggered sequences were applied for MRA: [TSE-Db] T2-weighted dark-blood TurboSpinEcho (2.0 x 1.1 x 4 mm3); [trueFISP] 2D-steady-state-free-precession (2.2 x 1.8 x 2 mm3); [NAV] respiratory-gated, T2-prepared 3D-trueFISP (1.3 x 1.3 x 1.3 mm3). ECG-gated-CT angiography (CTA) (16-row CT, 1 mm collimation) served as …
Corrigendum to Patterns of ascending aortic dilatation and predictors of surgical replacement of the aorta: A comparison of bicuspid and tricuspid ao…
2020
The authors regret that the author name of Romano and Raffa are incorrect. The corrected author's name are Romano G and Raffa GM. The authors would like to apologise for any inconvenience caused.