Active clinical trials for "Constriction, Pathologic"

The purpose of this study is to evaluate the clinical outcomes of transcatheter aortic valve replacement (TAVR) in patients with bicuspid aortic valve stenosis.

Aortic stenosis is the most common adult valvular heart disease in the western world. Heart failure and sudden cardiac death are complications associated with aortic stenosis. In symptomatic individuals, valve replacement is often the only effective treatment. However, there are no good markers to identify patients who may benefit from early surgery before symptoms developed. The purpose of the study is to test the hypothesis that the presence heart muscle scarring on the cardiac magnetic resonance imaging may predict a worse outcome in patients with aortic stenosis, and thus may be helpful in identifying patients for early valve replacement.

The study is aimed to develop a new reaction-time based method for examining the visual field and to study the effect of refractive error on the magnification of a fundus photograph in order to evaluate the true size of a retinal feature.

The purpose of this study is to study the evaluation of the use of metal stents as part of the treatment of benign biliary strictures.

The purpose of this study is to test the prognostic value of autonomic markers in patients with aortic stenosis.

It is not clearly understood what causes tracheobronchomalacia (weakening of the windpipe and airways) or tracheal stenosis (narrowing of the windpipe). We plan to take biopsies (small pieces of tissue) and brushings (to collect the cells that form the lining of the airway) from the airways of patients with these diseases and analyze these samples in a laboratory to try and determine the mechanism of disease. We will compare the results with that of patients with normal airways.

This study is planned to investigate the incidence of intraoperative floppy iris and its relationship with pseudoexfoliation, diabetes, hypertension as well as systemic alpha-1 adrenergic blocker use.

Postoperative stenoses of the pulmonary artery vascular system seldom occur alone; they are frequently found in connection with congenital heart defects or malformation syndromes. The resulting increase of afterload represents a serious pressure load for the right ventricle. Depending on the number and severity of the stenoses, gradual functional right ventricular failure is to be expected. Due to limited clinical experience, there has not yet been a consensus concerning the indications for the different therapeutic strategies (balloon dilatation, stent implantation, surgical dilatation techniques). Up to now, only few investigators in few centres use stents as therapy. Therefore, systematic multicenter investigations assessing larger groups of patients undergoing this procedure are not yet available. The same applies to other novel dilatation techniques, such as the use of the "cutting balloon" as therapy for rigid valve stenoses. By comparing and analysing different invasive forms of treatment (balloon dilatation, stent implantation and surgery), we expect to achieve an optimisation of therapy. In the study, the outcomes of different strategies as practiced now in German cardiological centers will be compared and the main factors influencing the results will be determined. On the basis of a standardized investigation before and one year after the intervention, these comparisons with respect to the reduction of stenosis and corresponding changes of right ventricular functional and anatomical changes are carried out correcting for known confounders. The assessment of the different included invasive and non-invasive diagnostical procedures with respect to their ability to detect pathological findings and their changes as result of the treatment is an important secondary target of the study.

The purpose of this retrospective, observational study is to compare the profit of BAV and TAVI in different subtypes of serve aortic stenosis.

The aim of this study is to perform a multicentre, prospective, randomized, placebo controlled, double-blinded study to demonstrate the potential and beneficial effects of OVB in the prevention of recurrence of anastomotic stricture in children operated for esophageal atresia with an anastomotic stricture.