Search results for "aorta"
showing 10 items of 458 documents
Biomechanics of human ascending aorta and aneurysm rupture risk assessment
2021
Ascending aortic aneurysms (AsAA) and aortic dissections are life-threatening cardiovascular diseases. The main criteria for determining surgical intervention of AsAA are the maximum diameter or the increasing annual rate of the aneurysm. The mortality of the untreated aortic dissection can be 21% to 74%, depending on the delay of hospital admission.Our study aims to characterize the biomechanical properties of the ascending aorta and propose a patient-specific approach to assess the risks of rupture. The purpose of this PhD work is multifold.On the one hand, biaxial tensile tests were performed on AsAA samples obtained from one hundred patients with surgery of AsAA. The impact on the diffe…
Erythropoietin mediates tissue protection through an erythropoietin and common beta-subunit heteroreceptor
2004
The cytokine erythropoietin (Epo) is tissue-protective in preclinical models of ischemic, traumatic, toxic, and inflammatory injuries. We have recently characterized Epo derivatives that do not bind to the Epo receptor (EpoR) yet are tissue-protective. For example, carbamylated Epo (CEpo) does not stimulate erythropoiesis, yet it prevents tissue injury in a wide variety ofin vivoandin vitromodels. These observations suggest that another receptor is responsible for the tissue-protective actions of Epo. Notably, prior investigation suggests that EpoR physically interacts with the common β receptor (βcR), the signal-transducing subunit shared by the granulocyte-macrophage colony stimulating fa…
Tomographic image processing for the morphological and metrological study of Valsalva sinuses
2012
This Phd thesis deals with the design and the use of image processing tools in order to allow a reliable and objective study of the sinuses of Valsalva which are important cavities of the aortic root. The proposed methods can be applied on cine-MR sequences and CT examinations without any change in the settings between two examinations.Firstly, we studied the morphology of this anatomical area and its constant properties in all images of the dataset. Sinuses are one of the main bright organs with limited movements. Hence a new algorithm has been designed. It detects and characterizes each bright organ by a single trajectory. Various tools of mathematical morphology are used for this step, a…
Endovaskuläre Behandlung akuter Erkrankungender thorakalen Aorta
2002
Purpose To investigate the safety and efficacy of emergency treatment of acute aortic diseases with endovascular stent grafts. Methods In 11 patients (median age 55 years, range 18 - 85) with acute complications of descending aortic diseases endovascular emergency treatment was performed: traumatic aortic rupture (n = 4), penetrating ulcer with aortobronchial fistula or hematothorax (n = 4), acute type B dissection (n = 2, one with penetration, one with subacute mesenteric ischemia), and symptomatic aneurysm of the thoracic aorta (n = 1) with pain and diameter progression. 15 stent grafts were implanted (Talent n = 11, Vanguard/Stentor n = 4). Stent extension was necessary in 4 cases. In 2 …
Tumor mixoide de cayado aórtico: a propósito de un caso
2010
Las neoplasias aórticas son una rara causa de embolia sistémica y normalmente se descubren a partir de un defecto de repleción en las pruebas de imagen. Presentamos el caso clínico de un varón de 52 años de edad que sufre un episodio de isquemia aguda del miembro superior derecho a raíz de la cual es descubierta y tratada una neoplasia íntimal de cayado aórtico. Se aporta revisión de la literatura sobre la evidencia en el manejo de este tipo de entidades.Aortic tumors are a rare cause of systemic embolisation and usually discovered through an image of repletion defect. We present the case of a 52-year-old male with an acute ischemic right upper limb which led to the diagnosis and treatment …
Radiologic and Intraoperative Finding of Intimal Tear in Type A Intramural Hematoma of the Aorta
2019
AbstractAortic intramural hematoma (IMH) is described as “dissection without intimal tear” due to rhexis of vasa vasorum, which results in bleeding within the tunica media in the absence of intimal disruption or blood flow communication. The aim of our study is to validate perioperative evidence of intimal entry tear in IMH patients and to suggest that this entity may represent a part of a disease and not a separate disease.
Evidence of intimal tear in type A intramural hematoma of the aorta: A case series
2017
Highlights • We report two cases of type A intramural hematoma of the aorta. • We found radiological and intraoperative evidence of an intimal tear. • This finding supports the hypotesis that IMH belong to “aortic dissection” disease.
Desarrollo de un modelo predictivo de mortalidad a largo plazo y complicaciones relacionadas con la endoprótesis, en la reparacion endovascular de an…
2015
Desde el inicio de la reparación endovascular de aneurismas de aorta abdominal infra renal, la progresión de dicho tratamiento ha superado en numero al realizado anualmente mediante cirugía abierta convencional, en la mayoría de servicios de Cirugía Vascular. A ello ha contribuido principalmente la menor mortalidad operatoria los 30 días y al atractivo que supone para pacientes un procedimiento menos agresivo y para los profesionales, el ofrecer una alternativa en casos en los que la cirugía abierta sería inasumible por elevado riesgo. Sin embargo se pueden señalar dos puntos de controversia en dicha tendencia: -La menor tasa de mortalidad postoperatoria, puede hacer que se ofrezcan alterna…
A combination of umbilical artery PI and normalized blood flow volume in the umbilical vein: Venous–arterial index for the prediction of fetal outcome
2008
Abstract Objective The objective was to assess the diagnostic power of the umbilical venous–arterial index (VAI) as a combination of the pulsatility index in the umbilical artery and the normalized blood flow volume in the umbilical vein for the prediction of poor fetal outcome. Study design This was a prospective clinical study in which the umbilical artery PI (UAPI), the normalized umbilical vein blood volume flow rate ( n UV; ml/min/kg estimated fetal body weight), the venous–arterial index (VAI; n UV/UAPI), and the pulsatility index (PI) in the umbilical artery (UA), uterine artery (utA), middle cerebral artery (MCA), and aorta were determined in 181 fetuses once (at between 17 and 41 w…
Human Fetal Aorta Contains Vascular Progenitor Cells Capable of Inducing Vasculogenesis, Angiogenesis, and Myogenesis in Vitro and in a Murine Model …
2007
Vasculogenesis, the formation of blood vessels in embryonic or fetal tissue mediated by immature vascular cells (ie, angioblasts), is poorly understood. We report the identification of a population of vascular progenitor cells (hVPCs) in the human fetal aorta composed of undifferentiated mesenchymal cells that coexpress endothelial and myogenic markers. Under culture conditions that promoted cell differentiation, hVPCs gave rise to a mixed population of mature endothelial and mural cells when progenitor cells were stimulated with vascular endothelial growth factor-A or platelet-derived growth factor-betabeta. hVPCs grew as nonadherent cells and, when embedded in a three-dimensional collagen…