View clinical trials related to Constriction, Pathologic.
Filter by:Low-flow, low-gradient (LF-LG) aortic stenosis (AS) may occur with depressed (i.e. Classical LF; CLF) or preserved (i.e. Paradoxical LF; PLF) LV ejection fraction (LVEF) and both situations are amongst the most challenging encountered in patients with valvular heart disease. Although, CLF-LG AS is recognized has an important clinical entity, current ACC/AHA-ESC guidelines however do not provide precise recommendations for clinical management of these patients . PLF-LG AS is a new entity recently described by our group, which is characterized by more pronounced LV concentric remodeling with smaller LV cavity size and a restrictive physiology leading to impaired LV filling, altered myocardial function, and a low-flow state. Up to recently, this entity was often misdiagnosed, leading to underestimation of AS severity and inappropriate delays for aortic valve replacement surgery (SAVR). The two main challenges in patients with CLF- or PLF- LG AS are to distinguish between a true-severe (TS) versus a pseudo-severe (PS) stenosis and to accurately quantify the extent of myocardial impairment. Unfortunately, the traditional resting and stress echocardiographic parameters currently used to assess the severity of valvular and myocardial dysfunction in patients with LF-LG AS are far from being optimal, and as a consequence, quantification of disease severity and therapeutic management may not be appropriate in a substantial proportion of these patients. THE GENERAL OBJECTIVES of the TOPAS study are to develop and validate new parameters and biomarkers to improve the assessment of stenosis severity and myocardial impairment, the risk-stratification, and the clinical decision making in patients with LF-LG AS and to assess the impact of the different therapeutic strategies on patient outcomes.
Our main hypothesis on the present study is that new parameters such as risk-taking behavior, patients motivation, health related quality of life, new biomarkers and more precise echocardiography measures in addition to traditional parameters will improve pre-operative risk assessment in patients with AS and better guide patients and doctors in decision whether to operate or not.
Successful palliation of biliary obstruction is the main goal for reducing morbidity and mortality in patients with biliary disease and biliary obstruction related to cholangiocarcinoma. Surgical intervention for the sale is unfortunately complicated by a 30-day postoperative mortality rate of between 7 and 24%. Moreover, because of recovery time the quality of life following surgery is only improved in a minority. At present endoscopic insertion of a plastic or metal stent is the method of choice to relieve obstructive jaundice without the high morbidity and mortality associated with surgery. But this relief is unfortunately temporary since stents tend to become obstructed and the fact that effective biliary drainage in the proximal lesion is challenging. Photodynamic Therapy (PDT) is a new therapeutic approach that specifically targets neoplastic cells. This therapy involves the intravenous administration of a photosensitizing agent followed by activation of the agent by illumination with non-thermal light of a specific wavelength, resulting in cell death from direct cytotoxicity and ischemic necrosis. A randomized controlled trial study by Ortner et all confirmed the significant advantage of PDT with regard to relief of jaundice, quality of life, and survival. In photodynamic therapy (PDT) the uniform distribution of externally applied light is desirable but often difficult to achieve. An optical fiber tip producing cylindrical or lateral light emission can facilitate the application of laser energy by direct implantation of the tip into solid tumors. However, currently used FDA approved glass diffusers used in standard of care PDT might break in the bile ducts causing injury since they are not meant to be used within bile ducts through an endoscope or choledochoscope. Hence, there is a need to evaluate and introduce more efficient and safe non-glass cylindrical optic fiber diffuser for photo dynamic therapy in the bile ducts. Recent studies have shown that the Pioneer plastic optic diffuser is safe and effective in photodynamic therapy, it can be also used via a choledochoscope. We aim to add to the clinical evidence by conducting an open label observational study trial using this fiber optic diffuser during photo dynamic therapy in the bile ducts.
Atherosclerosis is a chronic, systemic and progressive disease affecting different arterial blood vessels in the body. Atherosclerotic lesions silently progress from small plaques to severe stenosis and may remain asymptomatic for years. Unstable plaques and stenosis (also called vulnerable plaques), however, are prone to rupture leading to myocardial infarction, or stroke. The proliferation of the small arteries that are distributed to the outer and middle coats of the larger blood vessels (vasa vasorum) and within the atherosclerotic plaques (neovascularization) are inherently linked with the atherosclerotic plaque development, plaque inflammation and vulnerability. By injecting ultrasound contrast agents (microbubbles) into the blood stream, it is possible to detect this microcirculation of the vessel wall and the neovascularization within the atherosclerotic plaque using a contrast-enhanced ultrasound (CEUS) imaging technique. Particularly, CEUS of the carotid artery has been introduced as a non-invasive technique to improve detection of carotid atherosclerosis and to evaluate the presence of carotid plaque neovascularization which has emerged as a new marker for plaque vulnerability. The project investigates the predictive value of the detection of carotid plaque neovascularization on CEUS imaging in patients with asymptomatic carotid artery stenosis regarding the progression of the carotid atherosclerotic lesion and future vascular events including myocardial infarction, stroke or vascular intervention. The investigators hypothesize that neovascularization within the carotid lesion will significantly be more pronounced in patients with progressive carotid lesions and in patients suffering future vascular events during. The project will support the concept that intraplaque neovascularization is associated with plaque instability and vulnerability and therefore, the use of CEUS may provide an additional non-invasive, simple, safe, and reliable imaging modality to risk stratify individuals. The identification of vulnerable that are at increased risk of rupture by identification of intraplaque neovascularization is expected to improve the prediction of future vascular events and thus allow for better treatment selection. It will help the clinician to further risk stratify carotid stenosis. Particularly, it will help to identify unstable carotid stenosis that may already benefit from invasive therapy as carotid thromboendarterectomy and stenting.
Calcific aortic stenosis (AS) has become the most common cardiac disease after coronary artery disease and hypertension. Unfortunately no medical therapies have been proven to decrease either the progression of valve stenosis or the resulting adverse effects on myocardial remodeling and function. In light of the studies performed in PROGRESSA, it becomes obvious that: i) AS is a complex and actively regulated process that involves the interaction of several pathways including lipid infiltration and retention, chronic inflammation, osteogenic activation, and active mineralization within the valvular tissues; ii) AS is not a disease strictly limited to the aortic valve but rather a systemic disease that often involves calcification and stiffening of the aorta and impairment of LV function as a consequence of pressure overload. Our findings suggest that the dysmetabolic milieu linked to visceral obesity may accelerate the deterioration of the structure and function not only of the aortic valve but also of the aorta and of the left ventricle. These findings open new avenues of research and provide strong impetus for the elaboration of prospective studies focusing on the "valvulo-metabolic risk" in AS. The general hypotheses are: The metabolic abnormalities linked to visceral obesity accelerate (1) the progression of valvular calcification and stenosis, aortic calcification and stiffness; (2) the progression of myocardial fibrosis and dysfunction. The general objectives of the study are to elucidate the mechanisms implicated in the pathogenesis of AS and to identify the metabolic factors that determine the progression of: i) aortic valve calcification and stenosis; ii) myocardial fibrosis and dysfunction; and iii) clinical outcomes. This study will contribute to identifying the key metabolic determinants of AS progression and will pave the way for the future development of non surgical therapies for this disease. The results of this study would provide strong support to the realization of randomized trial to test the efficacy of lifestyle modification program or new pharmacological treatment aiming at the reduction of visceral fat and associated metabolic abnormalities in the AS population. Furthermore, this study will contribute to the identification of novel blood and imaging biomarkers of faster disease progression, which will help to optimize risk stratification and timing of AVR in the AS population.
Correlation study about Blood Pressure Variability and the prognosis of ischemic stroke with intracranial artery stenosis
Objective: To monitor and evaluate the change of intracranial hemodynamics and MCA stenosis after 24-week atorvastatin treatment using CEUS, CTA and DSA. Study design: Total 30 patients (60 arteries) will be enrolled in this study, who had MCA infarction within 6 months prior to screening, and has not received any statins treatment before stroke. Eligible patient will receive atorvastatin 40mg treatment for 24 weeks. Hemodynamics changes and MCA stenosis will be evaluated using CEUS at baseline, 3-month,and 6-month. MCA stenosis, bloodstream velocity, as well as clinical symptoms will be assessed at each visit and compared to baseline.
We hypothesized that fimasartan, a new generation ARBs, would improve exercise capacity and decrease the rate of progression of AS by modifying hemodynamic factors and reducing adverse LV remodeling favorably in patients with asymptomatic moderate to severe AS.
Intracranial arterial prominent stenosis (IAPS) is one of main cause of stroke especially in Asia. Although antiplatelet aggregative or anticoagulant agent and even surgical operation are used to treat patients with IAPS, the incidence of stroke occurrence still remains high. In addition, symptomatic IAPS most common cause continuous deterioration, thus, increase the incidence of stroke. Therefore, there is a good method to reduce the inceidence of stroke that is to prevent the progressive deterioration of IAPS. Huang-Chi-Wu-Wu-Tang is made of Astrgalus membranaceus (Fisch.) Gge , Paeonia lactiflora Pall , Cinnamom Twig , Zingiber officinale Rose , Ziziphus jujube Mill , and can treat hemiplegia in the traditional Chinese medicine writings. Astragaloside IV is a component of Astrgalus membranaceus, may reduce th cerebral infarction area in middle cerebral arterial occlusion mice. The investigators previous studies have known that paeoniflorin that a component of Paeonia lactiflora Pall can decrease the cerebral infarction area and neurological deficit in middle cerebral arterial occlusion rats. Therefore, the purpose of the present study was to investigate the effect of Huang-Chi-Wu-Wu-Tang on patients with IAPS.
Currently, very few centers offer Photodynamic therapy for unresectable Cholangiocarcinoma in the United States. Several European studies have reported the efficacy and safety of Photodynamic Therapy (PDT) for Cholangiocarcinoma, however, only a few studies have reported the same in the United States. The establishment of a registry to capture all PDT cases within and outside US can help the investigators evaluate a larger and non-ambiguous sample population. This would help the investigators evaluate the technical success rates, clinical success rates, feasibility and safety of PDT for unresectable cholangiocarcinoma. With more endoscopists considering PDT as a therapeutic option along with adjuvant treatment for cholangiocarcinoma, there is a need to further evaluate the efficacy and safety of such combined procedures as well. The ultimate objective is to assess if PDT with or without additional or adjuvant treatment options prolongs survival duration and improves quality of life in patients with unresectable cholangiocarcinoma. This multicenter registry has been initiated: - To document the impact of PDT on the clinical management of unresectable cholangiocarcinoma. - To assess the clinical and technical success rates of PDT for unresectable cholangiocarcinoma.