Active clinical trials for "Constriction, Pathologic"

The goal of this observational study is to investigate the incidence, current management practices, and outcomes in pediatric patients with HAC after liver transplantation. Research question: What are the overall incidence of HAC and the effectiveness of all treatment strategies for HAC after pediatric LT? What are the current management practices in the experience of centers, anticoagulant therapy, screening protocol, and assessment criteria for HAC after pediatric LT? The burden of participation is considered to be minimal, and limited to the questionnaires.

This is a phase I study to evaluate the safety, efficacy and tolerability of a novel tracheal replacement therapy using cadaveric de-cellularised tracheal scaffold and patients' own mesenchymal cells isolated from a sample of their bone marrow in patients' who suffer from severe tracheal malacia or stenosis.

Carotid artery stenosis due to atherosclerotic plaques accounts for an important cause of ischemic stroke. Current research seeks to risk stratify asymptomatic patients by characterizing rupture-prone plaques. Currently no single imaging modality can reliably identify those plaques before surgery. Recently, the 3D ultrasound (US) and the assessment of the mechanical stress on the vessel wall have been proposed as non-invasive tools that could play a role in the diagnostic work-up. Data of histological validation, however, are still needed. In this research, 3D US, non-invasive elastography, Finite Element Analysis of computed tomography angiography images and the study of the autonomic cardiovascular control will be used to identify preoperatively the vulnerable plaque in patients undergoing carotid endarterectomy. The results will be compared to that of histology of the removed plaque, aiming to provide a validation to each method for a possible application in the daily practice.

The objective of the present study is to investigate to hemodynamic profile at rest and during peak exercise of patients with suspected severe aortic stenosis and to compare flow- and pressure changes between high gradient patients and low gradient patients.

The retinal vessels have been shown to reflect vascular changes inherent to systemic pathologies, even when no ocular disease is identified. As such, the eye's vasculature is ableto serve as a window to the vascular health of the human body and a means of assessing systemic endothelial function. Optical coherence tomography angiography (OCTA) employs optical means to image all the retinal vascular layers and the choroid, providing an extremely detailed image of the microvascular network in a fast, reproducible and totally non-invasive way. As such, it is currently the best non-invasive way of having an image of human capillaries. Recently, OCTA has been used to study the retinal vessels' structure and function in several cardiovascular diseases. As an example of its predictive potential, reduced retinal microvascular density has been associated with the cardiovascular risk profile in patients admitted to the hospital for an acute coronary syndrome. Recent studies have also shown the retinal microvasculature density to be reduced in patients with carotid artery disease (CAD), namely carotid stenosis, and that endarterectomy increases retinal flow and vessel density.

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 families 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 purpose of this study is to explore the mechanism of cognitive impairment in patients with asymptomatic intracranial atherosclerotic stenosis(ICAS),and to examine the natural history and the pathogenesis of asymptomatic ICAS.

The purpose of this study is to evaluate the prognosis of coronary stenosis based on intracoronary Imaging.

Therefore, a high number of procedures is necessary to achieve EUS competency, but interobserver agreement still varies widely. Artificial intelligence (AI) aided recognition of anatomical structures may improve the training process and inter-observer agreement. Robles-Medranda et al. developed an AI model that recognizes normal anatomical structures during linear and radial EUS evaluations. We pursue to design an external validation of our developed AI model, considering an endoscopist expert as the gold standard.

In this multi-center prospective observational study within a cohort of symptomatic cerebral atherosclerotic stenosis (sCAS) patients, 850 subjects were planed to be enrolled to explore the relationship between cerebral autoregulation (CA) and stroke recurrence, determine the threshold values of CA parameter for predicting stroke recurrence associated with particular stenosis.