View clinical trials related to Constriction, Pathologic.
Filter by:Pyelo-ureteral junction syndrome is the most common urological abnormality in children. Functional MRI has been evaluated several times, and had shown good correlation with scintigraphy, but tends to over estimate results. Moreover, those studies included a small number of cases. Its sensitivity to detect crossing polar vessel is limited. We aimed to evaluate, in patients between 0 and 1 year old, the correlation between MRI and scintigraphy differential renal function. Our secondary objectives are : evaluation of MRI performances to detect polar vessel ; comparison of surgery times depending of MRI only realisation or MRI and scintigraphy realisation.
The purpose of this study is to create a state-wide biorepository and resource center for cerebrovascular diseases in Florida, which will include collecting medical history information and blood from subjects affected by cerebrovascular disease. The information and blood samples collected may be used in future research for the study of cerebrovascular disease and to learn about, prevent or treat other health problems.
• The aim of 3DP-FAST study is to analyze the accuracy of replicating cardiovascular anatomical structures using different techniques and to evaluate the feasibility of 3D printed models of aortic stenosis in guiding TAVI procedure. By conducting a comparative analysis of measurements achieved on CCTA images versus measurements obtained with a specialized projection platform by photogrammetry vs 3D printed models of various aortic valvular and perivalvular structures will be evaluated the accuracy of each step of image dataset processing. Furthermore, the study will evaluate the rate of valvular leak or peri-procedural complications such as embolic events or atrio-ventricular conduction block based on coronary computed tomography angiographic and ECG assessment at 1 year after enrollment.
Severe aortic stenosis is a condition with poor life expectancy once it becomes symptomatic. There are no prospective studies illustrating the utility of cardiopulmonary stress (CPX) testing in diagnosing and prognosticating patients with paradoxically low gradient and low flow severe aortic stenosis. We aim to prospectively investigate the utility of CPX in this patient population with the hypothesis that utilizing CPX parameters would better identify higher risk patients warranting further evaluation and possibly intervention sooner.
Rationale: Cardiovascular disease and cognitive diseases are closely related. Cognitive impairment is common (21-39%) among patients with severe aortic valve stenosis. The proof-of-concept CP-TAVI study showed that increased cardiac output following transcatheter aortic valve implantation (TAVI) was associated with increased cerebral blood flow. It is hypothesized that increased cerebral blood flow (CBF) subsequently leads to improved cognitive functioning. Additionally, silent micro emboli caused by crushing of the calcified native valve during TAVI may cause cognitive deterioration. If it could be predicted which patients are at risk for TAVI induced cerebral micro emboli, these patients could benefit from cerebral protection devices, preventing cognitive decline. Objective: The objectives of the CAPITA study are 1A) to identify whether an increase in cardiac output after TAVI is associated with an increase of global CBF; 1B) explore regional differences in CBF after TAVI; 1C) determine whether (global or regional) increased CBF is associated with improved cognitive functioning; 1D) identify patient and procedural characteristics associated with increased cardiac output, CBF and cognitive functioning; 2A) identify the incidence and volume of new white matter hyperintensities after TAVI; 2B) evaluate patient and procedural predictors for the increase in white matter hyperintensities volume, including baseline aortic valve calcification volume, measured with computed tomography; 2C) if aortic valve calcification volume predicts new white matter hyperintensities, define a cut-off value for high-risk patients; 2D) assess whether the increase in white matter hyperintensity volume is associated with deterioration of cognitive scores. Study design: Prospective observational study, measuring cardiac output (echocardiography), cerebral blood flow (arterial spin labelling magnetic resonance imaging) and cognitive functioning (neuropsychological test battery) prior to TAVI (<24 hours to <one week) and at 3 months follow-up. At one year follow-up, cardiac output and cognitive function will be assessed. Study population: Patients with severe aortic valve stenosis eligible for transfemoral TAVI (n=142). Main study parameters/endpoints: Cardiac output (L/min), cerebral blood flow (mL/100g/min, change in %, relative to baseline) and cognitive functioning (extensive neuropsychological testing 60-90 minutes).
The purpose of this registry is verifying the continued safety and effectiveness of the Optilume DCB clinical use in patients undergoing dilation of the urethral stricture.
The EMPIRE study confirms the technical performance of the new IMPERIA Delivery System and evaluates the safety and efficacy of the entire ALLEGRA THV System. The primary endpoint is device success rate at 7 days (discharge from index procedure or 7 days post implant, whichever comes first), as defined by VARC 2. Based on the outcomes of a study with a similar device and considering a drop-out rate of 5%, 107 patients need to be enrolled in the study.
Ischaemic Heart Disease (IHD) is the worlds leading cause of death. IHD is often caused by a narrowing of the coronary arteries, which prevents blood from flowing to the heart muscle, causing pain and damage to the heart. If an individual has a myocardial infarction (MI), parts of the heart that are damaged cannot be repaired. Therefore, it is important to identify and treat the narrowing of the arteries before an MI occurs. At present there are 2 main methods of identifying narrowing of the arteries. The first is an invasive procedure, the other using a CT scan. Whilst both methods are effective, they entail risk. The invasive procedure can damage the coronary arteries, whilst the CT scan exposes patients to radiation and contrast, which can increase the risk of cancer and allergic reactions. Magnetic Resonance (MR) scanning is an alternative to these methods, but it has been limited in use in the past due, in part, to the high technical knowledge required to obtain images. In addition, there is a degree of subjectivity in the selection of the mid-diastolic rest period, potentially affecting consistency of results. This means it is difficult to use in a day-to-day hospital environment. However, recent technological developments using artificial intelligence mean that images can be acquired in a more automated and consistent fashion. This new scan has yet to be tested in a clinical trial. Therefore, the objective of the clinical study is to test this new scan to determine its efficacy. 230 patients at 5 sites at risk of coronary artery disease, who have been referred for invasive coronary angiography, will undergo both their angiography and the new MR scan. The MR scan will then be compared to CCTA for diagnostic accuracy and image quality. The investigators hypothesise that the new MR scan will have the same diagnostic accuracy as invasive coronary angiography, with no differences in interpretation of the images across the 5 different hospitals. If proven effective, this would demonstrate that MR scanning of the coronary arteries could prove a safe, clinically useful alternative to both CT scanning and invasive assessment of coronary artery narrowing. In addition, if there is no difference across different locations, it would demonstrate that these scans can be performed consistently, facilitating implementation on a healthcare-system wide basis.
The optimal screening methods for coronary insufficiency, a frequent and pejorative complication in diabetics, are subject to debate, particularly in situations of silent myocardial ischemia. The contemporary strategy consists of pre-selecting asymptomatic patients at very high cardiovascular (CV) risk by performing a coronary calcium score. If this is found to be high >300 AU (Agatston units), the patient is suspected of being at high risk of silent myocardial ischemia (SMI), and the assessment is completed to exclude the presence of coronary artery disease likely to benefit from revascularization. The complementary evaluation consists in evaluating the myocardial perfusion to judge the perfusion repercussions. The most common examination to date is myocardial scintigraphy, because stress tests are too frequently submaximal in diabetics. However, the reproducibility of scintigraphy is controversial and their sensitivity and specificity are debated in this indication. This problem is similar in stable symptomatic coronary diabetic patients for whom an indication for functional examinations is justified. The double-energy double-layer spectral scanner (SDEDC) could now become a relevant tool in this field, since it can combine not only anatomical data (identification of coronary stenosis) but also functional data (myocardial perfusion) during a stress protocol. thanks to the spectral images which make it possible to measure the tissue concentration of intramyocardial iodine downstream of the considered stenosis.
The field of research for this study is tissue engineering and the utilization of a bioengineered collagen implant as a substitute biomaterial for conventional buccal mucosa in substitution urethroplasty of distal urethral strictures.