Active clinical trials for "Constriction, Pathologic"

The aortic valve is the main outlet valve from the heart. This valve can become diseased and narrowed when it needs to be replaced with an artificial valve. Currently, this is the commonest reason for someone to undergo a heart valve operation in the UK. Unfortunately, there are no medical treatments that can prevent or delay the progression of this disease process. Here, the investigators propose to use new state-of-the-art imaging techniques to better understand the disease process so that the investigators can effectively design and assess potential new treatments. The ultimate aim is to stop this disease before patients need to have surgery. In addition the investigators believe this technique will allow us to predict the rate of progression of the disease

This is a prospective, single-arm, open-label, multi-center, observational study to assess the acute safety and efficacy of MINI TREK RX 1.20 mm, for descriptive purposes only.

The purpose of this study is to determine patient variables, physician presenter variables, and information variables that might affect clinical decision making in asymptomatic carotid stenosis. The hypothesis is that information variables are the most significant determinant of clinical decision making.

PURPOSE: The purpose of this clinical trial is to study the cost-effectiveness ratios of diagnostic strategies for the imaging assessment of symptomatic carotid stenosis. MATERIALS AND METHODS: The diagnostic accuracies of Doppler ultrasound (DUS), contrast-enhanced magnetic resonance angiography (CEMRA) and computed tomography angiography (CTA) were compared with digital subtraction angiography (DSA) in a multicenter study (CARMEDAS; 206 patients assessable) and in a meta-analysis (for CEMRA and CTA). The direct costs of each imaging method were calculated in 2 university medical centers. Eight hypothetical models were studied with DUS considered as the first-line imaging method and either CEMRA or CTA or DSA as the second or third line method. The effectiveness criterion was the number of potential avoided strokes for each strategy and for 1000 patients.

This study is to evaluate the correlation between muscle atrophy (MA), sagittal alignment, and stenosis degree in patients with lumbar spinal Stenosis (LSS). From existing radiological images, specific radiographic parameters will be extracted. General Information (Age, sex, levels of stenosis, duration of symptoms) will be extracted from patient files.

This study aims to evaluate ocular changes in patients with carotid artery stenosis by optical coherence tomography angiography before and after carotid artery revascularization procedure.

Digital Variance Angiography (DVA) is a new tool in medical imaging with proven image quality reserve. The previously observed quality reserve of Digital Variance Angiography (DVA) in lower extremity angiographies, allowed to lower radiation exposure by 70 % during DSA in lower extremity diagnostic angiographies with non-inferior image quality. The aim of this study is to apply this non-inferior image quality and use it for radiation exposure reduction in diagnostic lower limb angiography. The project would prospectively block-randomise (50:50) patients, who undergo elective diagnostic angiography into two groups: a comparator group examined by means of conventional DSA using a standard care protocol (Siemens Artis Zee, Extremities Care setting, 1.2 µGy/frame) (Group B) and a study group examined by means of DVA using a low-dose protocol (0.36 µGy/frame corresponding to 70% decrease of radiation dose) (Group A). During each procedure the investigators record radiation exposure (cumulative dosage, dose area product) and contrast media usage and procedural time then compare the results of the groups. Qualitative image review is done to compare conventional DSA and reduced radiation exposure DVA images after image acquisition. Our hypothesis is that with the previously proven non-inferior image quality, the investigators will be able to reduce radiation exposure of the participants and also staff members in everyday clinical practice.

To assess safety and effectiveness in the long term of percutaneous insertion of Biodegradable (BD) Biliary Stents for the treatment of benign biliary strictures, in a single center experience.

To evaluate during a 7 months period the efficacy, safety and accuracy of percutaneous transluminal forceps biopsy combined with transhepatic biliary drainage in patients with biliary stricture

Gastric conduit ischemia or anastomotic breakdown after esophagectomy with cervical esophagogastrostomy often cause severe complications, such as leakage, necrotic organs, and strictures. Thus, the purpose of this study is the safety and efficacy of endoscopic evaluation about reconstructive organs after esophagectomy. The investigators evaluate endoscopic predictions using classifications in acute phase after esophagogastrostomy.