Search results for "Stent"
showing 10 items of 1166 documents
Kontrastverstärkte MR-Angiographie abdomineller Gefäßean einem 1.0 T-System*
2000
Purpose To evaluate the efficacy of breath-hold, three-dimensional, contrast-enhanced magnetic resonance angiography with a 1.0 T system for imaging the abdominal vessels in comparison to conventional arteriography (CA). Methods The abdominal aorta and visceral arteries were studied in 54 patients (60 examinations) on a 1.0 T scanner using an ultrafast gadolinium-enhanced gradient-echo sequence with the following parameters: TR/TE = 3.8/1.4 ms, flip angel 25 degrees, matrix 198 x 256, field 380-420 mm, pixel size 1.9 x 1.48 mm2, slice thickness 1.5-2.5 mm, acquisition time 22-26 sec. Individual circulation times were determined by a test bolus before each MR angiography. Conventional arteri…
Early results of a low-profile stent-graft for thoracic endovascular aortic repair
2020
Purpose To assess outcomes of a low-profile thoracic stent-graft in the treatment of thoracic aortic pathologies. Methods A retrospective analysis of all consecutive patients with aortic thoracic pathologies treated with the RelayPro device in two university hospitals between October 2018 and July 2019. Results 23 patients (65% men; mean age 63.4 ± 15 years) were treated. Pathologies included aortic dissections (n = 10), 5 residual type A (22%) and 5 type B (22%), 6 degenerative aortic aneurysms (26%), 4 penetrating aortic ulcers (17%), and aortic erosion, intramural hematoma and aortic rupture (n = 1 and 4% in each case). Two cases (9%) were emergent and two urgent. Proximal landing was a…
Thoracic Endovascular Aortic Repair (TEVAR) for the treatment of aortic diseases: a position statement from the European Association for Cardio-Thora…
2012
Thoracic endovascular aortic repair (TEVAR) is an emerging treatment modality, which has been rapidly embraced by clinicians treating thoracic aortic disease.1–4 Fundamentally, it is a far less invasive approach than open surgery and its availability and relative ease of application has changed and extended management options in thoracic aortic disease, including in those patients deemed unfit or unsuitable for open surgery. In the operating room, this requires considerable perceptual, cognitive and psychomotor demands on the operators. The dramatic expansion of TEVAR activity has necessarily prompted a requirement to systematically consider the indications, appropriateness, limitations and…
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…
Total occlusion of aortic arch in a 62-year-old man presenting with acute myocardial infarction
2011
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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…
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 …
Transcervical approach for carotid artery stenting with transitory reversal flow: Case report
2021
Introduction Carotid artery stenting (CAS) has been indicated as an alternative to carotid endarterectomy in high risk patients. Sometimes, an aortic arch can be anatomically unfavourable for CAS. Herein we report our experience in a case of CAS with transcervical approach. Presentation of case A 77-year-old male was referred to our hospital for severe subtotal occlusion of the left internal carotid artery. He had a past medical history of radiation to the head and neck for laryngeal cancer. Previous CT-angiography had shown a type III aortic with bovine arch. CAS via transcervical approach was performed with transitory reversal flow during the placement of RX Spider Filter 6 Fr (Medtronic,…
Transcatheter Heart Valve Implantation in Bicuspid Patients with Self-Expanding Device
2021
Bicuspid aortic valve (BAV) patients are conventionally not treated by transcathether aortic valve implantation (TAVI) because of anatomic constraint with unfavorable outcome. Patient-specific numerical simulation of TAVI in BAV may predict important clinical insights to assess the conformability of the transcathether heart valves (THV) implanted on the aortic root of members of this challenging patient population. We aimed to develop a computational approach and virtually simulate TAVI in a group of n.6 stenotic BAV patients using the self-expanding Evolut Pro THV. Specifically, the structural mechanics were evaluated by a finite-element model to estimate the deformed THV configuration in …
Ma‘dûle Önermelerde Varlıksal İçerik Sorunu: Fahreddin er-Râzî-Kutbüddin et-Tahtânî Tartışması
2019
This paper addresses discussions in post-Avicennan Arabic logic on the definition of metathetic propositions and their status in relation to existential import requirements, focusing on the arguments made by Fakhr al-Dīn al-Rāzī (d. 606/1210) and the counter-arguments by Quṭb al-Dīn al-Rāzī al-Taḥtānī (d. 766/1365), who both establish their positions in the framework drawn by the most prominent figure in the tradition of classical Arabic logic, Avicenna (Ibn Sīnā, d. 428/1037). In the latter’s works, the problem of the existential import requirement in metathetic propositions (ma‘dūla) are thoroughly discussed and Avicenna seems to have presumed the existential import as a truth-condition f…