Active clinical trials for "Constriction, Pathologic"

Investigators sought to demonstrate that the increase in the stroke volume during a dobutamine stress echocardiography might impact the prognosis of a patient addressed for a low flow low gradient suspected severe aortic valve stenosis.

The purpose of this prospective study is to compare the diagnostic utility of two techniques (brush cytology + FISH and brush cytology + free DNA analysis) in the diagnosis of biliary strictures. Histologic diagnosis (biopsies) in conjunction with clinical and/or imaging follow-up will serve as the gold standard for diagnosis of malignancy. In order to do this the investigators will ask study participants to have a small volume of fluid obtained from the bile duct sent for additional testing at RedPATH. In some patients additional brushings will be obtained for FISH testing (this adds <2 minutes to ERCP and only associated risk is increased procedure duration). The investigators hypothesize that the use of cytology +DNA analysis has a higher sensitivity and accuracy when compared to cytology +FISH in patients with biliary strictures. Primary aim: To compare the sensitivity and accuracy of the two techniques (brush cytology + FISH and brush cytology + free DNA analysis). Histologic diagnosis (histology from biopsy or cytology for fine needle aspiration) in conjunction with clinical and/or imaging follow-up will serve as the gold standard for diagnosis of malignancy. Secondary aims: To evaluate the diagnostic yield of malignancy when all three techniques (cytology, FISH and DNA analysis) are used. To evaluate the added value of biliary forceps biopsies, when used in conjunction with cytology, FISH and DNA analysis.

The purpose of this study is to create a long-term storage of bile and brushings of pancreato-biliary duct in patients diagnosed with pancreato-biliary stricture for future research. Recently, a lot of research has been done to test for certain markers in the bile and brushings to detect cancer in a stricture. The samples will be used to measure biomarkers (proteins) in biliary diseases.

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.

The improvement in uroflow and postvoid residual urine in children after urethral meatotomy for meatal stenosis. The hypothesis is that there is an improvement in both parameters, thus justifying the procedure.

The investigators' rationale was to evaluate whether a 64-slice CT scanner allows accurate measurement of computed tomographic changes in coronary artery flow profiles and whether CT flow measurements are suitable for classifying the significance and hemodynamic relevance of a stenosis and thereby supplement as a functional parameter for morphological stenosis analysis.

OBJECTIVES: I. Identify and characterize the gene causing diaphyseal medullary stenosis with malignant fibrous histiocytoma of the bone. II. Determine the clinical manifestations of this disease in these patients.

Pain sensitivity would be associated with surgical outcomes after lumbar spine surgery.

Aortic stenosis (AS), or narrowing of the aortic valve, is the commonest condition requiring valve surgery in the developed world. It is currently not known what determines who will go on to develop symptoms. Exercise testing may be able to identify these patients better than the severity of the narrowing itself, but with some limitations. The purpose of this study is to compare whether MRI scanning or exercise testing can better identify patients with AS who are likely to benefit from surgery. Design: The investigators will measure blood flow to the heart muscle with MRI scanning and perform exercise testing in 170 patients with AS and follow them for up to up to 2 years. Expected outcomes: MRI scanning will more accurately identify those patients with AS who will need surgery during this period. Anticipated Health Benefits: improved selection of patients with AS who are likely to benefit from early surgery. This is likely to reduce deaths in such patients.

According to the 2006 ACC/AHA practice guidelines for valvular heart disease, patients with asymptomatic aortic stenosis(AS) should have screening transthoracic echocardiograms (TTE) performed annually for severe disease, every 1-2 years for moderate disease and every 3-5 years for mild disease. This results in a multitude of screening studies in the investigators patient population. 3M has developed a new stethoscope and phonocardiography software capable of identifying the peak intensity of the AS murmur and tracking it as it moves towards the second heart sound potentially indicating increasing severity of disease. Currently there exists no data to demonstrate that the aortic stenosis acceleration index (ASAI) correlates to disease severity or progression of disease. The ASAI measures the timing of the peak intensity of the systolic murmur and compares it to the total time in systole (S2-x/s2-s1) where s1 is the first heart sound; S2 is the second heart sound and x with the time between S1 and the peak intensity of the murmur. In this study the investigators propose to correlate the ASAI to standard TTE measurements of aortic stenosis severity.