View clinical trials related to Constriction, Pathologic.
Filter by:Endoscopic retrograde biliary drainage with a self-expandable metal stent (SEMS) has been used as a principle palliative method of distal biliary obstruction in patients with pancreaticobiliary cancers. With potentially curative surgical resection being impossible, the maintenance of successful biliary drainage through patent stent has been regarded as the key to improve the quality of life and survival of patient, because it could prevent biliary infection or liver failure, and give patients opportunities for anti-cancer chemotherapy and/or radiotherapy. Although SEMSs have been reported to be superior to large bore plastic stents in terms of stent patency, they still have some controversial issues to resolve in relation to stent dysfunction and adverse event. It has been widely accepted that covered SEMSs designed to overcome the stent failure of uncovered SEMSs related to tumor ingrowth, have significant higher rate of stent migration as well as tumor overgrowth. Therefore covered SEMSs did not show the clear clinical excellence in the cumulative stent patency over uncovered SEMSs, despite some clinical results of randomized trials favor to covered SEMSs. From the perspective of adverse events such as pancreatitis and cholecystitis, conflicting results have been produced. It was initially assumed that covered SEMSs could cause the higher incidence of pancreatitis and cholecystitis attributed to occlusion of pancreatic duct and cystic duct by covering materials. However, no significant difference was found with regard to the incidence of pancreatitis and cholecystitis between covered and uncovered SEMSs in several randomized trials and meta-analysis. The aim of the current study is to compare the cumulative stent patency of partially covered and uncovered SEMS as a primary objective, and investigate overall patient survival, stent dysfunction-free patient survival, and incidence of adverse events including stent dysfunction as secondary objectives.
Aortic stenosis (AS) is the most common valvular heart condition in the United Kingdom and the Western world. Surgery for severe AS prior to symptom onset is controversial. Conventionally changes in valve area and gradient are used to time intervention but myocardial changes may be more predictive of surgical need. This study aims to elucidate the role of diffuse myocardial fibrosis as a prognostic marker, implementing a novel, non-invasive MRI technique to measure it. Design: The investigators will measure diffuse myocardial fibrosis in 150 patients with severe narrowing of the aortic valve before and one year after valve replacement. Expected outcomes: Diffuse myocardial fibrosis measured by MRI scanning will predict outcome after surgery in aortic stenosis. Anticipated Health Benefits: Identify patients with higher post operative morbidity and mortality, who may benefit from earlier valve replacement.
ABSORB IV is a prospective, randomized (1:1, Absorb BVS to XIENCE), single-blind, multi-center study, registering approximately 2610 subjects from approximately 140 sites in the United States and outside the United States. ABSORB IV is a continuation of ABSORB III (NCT01751906) trial which are maintained under one protocol because both trial designs are related. The data from ABSORB III and ABSORB IV will be pooled to support the ABSORB IV primary endpoint. Both the trials will evaluate the safety and effectiveness of Absorb BVS. The ABSORB IV Randomized Controlled Trial (RCT) is designed to continue to evaluate the safety and effectiveness as well as the potential short and long-term benefits of Abbott Vascular Absorb™ Bioresorbable Vascular Scaffold (BVS) System, and the Absorb GT1™ BVS System (once commercially available), as compared to the commercially approved, control stent XIENCE.
This is a prospective, single blinded, randomized study of EndoMAXX Endoluminal Valve Technology (EVT) Fully Covered Esophageal Stent with Valve for the treatment of malignant strictures of the lower esophagus. The purpose of this study is to evaluate improvement of dysphagia due to esophageal stricture with EndoMAXX Endoluminal Valve Technology (EVT) Fully Covered Esophageal Stent with Valve (investigational device) compared to the EndoMAXX Fully Covered Esophageal Stent (reference device).
The purpose of this study is to evaluate the safety and performance of the HLT System in patients with severe aortic stenosis who present at High Risk for aortic valve replacement surgery.
Aortic stenosis is a common valvular heart disease, affecting mainly people over age 60. It is characterized by years to decades of slow progression followed by rapid clinical deterioration and a high death rate once symptoms develop. The onset of symptoms confers a poor prognosis: patients die within an average of five years after the onset of angina, three years after the onset of syncope, and two years after the onset of heart failure symptoms. The overall mortality rate is 75% at three years without surgery. Drug therapy for it remains ineffective, and aortic valve replacement is the only recommended long-term treatment.
The purpose of this study is to document the performance of a new Fully Covered Self Expanding Metal Stents (FCSEMS) for treatment of refractory pancreatic duct strictures in patients with painful chronic pancreatitis.
Aortic stenosis is a condition whereby one of the heart valves (aortic valve) becomes narrowed, due to calcium deposition, over time. This can lead to chest pain, heart failure and sudden death. It is the commonest valve disease requiring surgery in the developed world and as the population becomes increasingly older, it is predicted that the prevalence of aortic stenosis will double in the next 20 years. Currently the only treatment is replacement of the aortic valve. Whilst this is excellent treatment, not everyone is suitable for it. The primary objective of our study is to determine whether 2 drugs used in the treatment of osteoporosis (a condition of bone thinning) can halt/retard the progression of aortic stenosis. This is on the basis that studies have suggested that altered regulation of calcium metabolism may be an important mechanism perpetuating the disease. Both drugs work by reducing calcium release into the bloodstream from bones and therefore calcification of the aortic valve. 150 patients will therefore be randomly allocated to either of the trial drugs which are denosumab,the bisphosphonate (alendronic acid), or a placebo. Positron Emission Tomography (PET) scanning is a technique where biochemically active molecules are injected and are taken up at sites of ongoing calcification activity where they emit radiation and can be detected by the PET scanner. We have previously shown that this technique can demonstrate areas of newly developing calcification on an aortic valve. We therefore propose that patients receiving bisphosphonates or denosumab will have reduced evidence of active calcification and slower progression of their disease at two years as assessed by Echocardiography (ultrasound) and a change in their calcium score (quantity of calcium on the aortic valve measured using Computed Tomography [CT] ). The data from this study will then be used to design a larger trial.
The primary objective of this study is to determine the reasons for balloon aortic valvuloplasty (BAV) in the current clinical setting and to determine the outcomes of BAV in patients with aortic stenosis. The ultimate aim is to establish the safety, effectiveness, and appropriate role of BAV therapy as definitive therapy (palliation) or as a "bridge" to surgical aortic valve replacement (SAVR) or transcatheter aortic valve replacement (TAVR).
Endoscopic treatment of benign biliary strictures can be challenging. Balloon dilation and/or plastic stent placement are currently the most popular techniques. Partially covered self-expandable metallic stents have also shown to be effective but can be difficult to remove. A novel fully covered metallic stent has recently been developed. The aim of this study was to prospectively evaluate the placement of fully covered self-expandable metallic stents (FCSEMS) in this setting.