Active clinical trials for "Constriction, Pathologic"

This study evaluates the dentoskeletal effects of the expander with differential opening in orthodontic patients in the mixed dentition. Half of participants will undergo rapid maxillary expansion (RME) using the expander with differential opening, while the other half will undergo RME using the conventional Hyrax expander.

The purpose of this study is to evaluate the clinical and radiological results of surgical treatment of one-level central stenosis of the lumbar spine using traditional open approach (PLIF) and a minimally invasive procedure (MIS TLIF). According to the hypothesis, we assume that unilateral approach of MIS TLIF allows for adequate bilateral decompression of one-level central stenosis of the lumbar spine. Using MIS TLIF it is possible to perform reliable fixation of a spine segment and the formation of a complete intervertebral bone fusion. The long-term clinical results of surgical treatment with minimally invasive technologies (MIS TLIF) and traditional open approach (PLIF) suspected to be comparable.

This is a pre-market clinical investigation aiming to evaluate the safety and effectiveness of MicroPort™ CardioFlow VitaFlow™ Transcatheter Aortic Valve System for the treatment of severe aortic stenosis.

The purpose of this study is to determine the effectiveness of minimally invasive surgical technique over the traditional open surgical procedure in patients with degenerative lumbar stenosis

Transcatheter aortic valve replacement (TAVR) has a high risk and a high mortality rate in the treatment of aortic stenosis/regurgitation patients with cardiac insufficiency. The investigators aim to discuss the clinical efficacy of extracorporeal life support system(ECLS) during TAVR procedure in severe aortic lesion under very low ejection fraction (EF).

Primary sclerosing cholangitis (PSC) is a chronic inflammatory disease of the biliary tract of unknown origin. Around 50% of patients develop during their disease course narrowing of the main bile duct with corresponding increase in symptoms such as itching, jaundice and abdominal pain. These narrowings can be treated by balloon dilatation or temporary insertion of a plastic endoprosthesis. However, it is not known which of these two therapeutic modalities is best. This study aims to compare both techniques in order to determine which is best in terms of postponing recurrence of the narrowing, safety and costs.

Overall Objective: To evaluate the efficacy of an interventional walking program on the quality of life and functional status of patients with Lumbar Spinal Stenosis, post-surgery, using subjective (VAS, ODI, RMDQ, SF-36), and objective measures (triaxial accelerometry, step count, weight). Design and Methods: Two groups of subjects will be examined; patients diagnosed with lumbar spinal stenosis (LSS) that progress to surgical management, with one group of subjects staring on the walking program at 2 months postop, and the other group starting on the walking program at 3 months postop. Subjects who agree to participate will be assessed (assessments listed below) after the diagnosis preoperatively and 2 months postoperatively. One half of the group will start the walking program at the 2 months postop visit and be assessed again at the end of the walking program, the other half will be assessed again at 3 months postop and start the walking program at that time and be assessed again at 4 months postop. All subjects will be contacted by phone during their walking program to allow for questions from the subjects and to offer support and encouragement. Subjects will be given instructions and a daily diary to track steps taken each day (appendix A). Subjects will be recruited from the referrals to the practices of the Orthopedic and Neurosurgery Spine Surgeons at the Health Sciences Centre in Winnipeg. This encompasses the majority of new and currently managed cases in the Manitoba and Northwestern Ontario. Subjects will be between the ages of 18 and 90. Male and female subjects will be recruited into the study. All LSS patients will demonstrate intractable neurogenic claudication and radiographically confirmed lumbar spinal stenosis. Exclusion criteria will be any previous lumbar spine surgery, the existence of significant co-morbidity (e.g. neurologic or cardiac condition, disease, etc.) of any form, and any other physical limitations (musculoskeletal injury) preventing the subject from participating in regular activity and the walking program. Subjects participating will be required to speak English.

The consequence of aortic valve stenosis (AVS) is increased pressure load on the left ventricle which causes left ventricular (LV) hypertrophy, and myocardial stretch will cause activation of cardiac peptides and activation of the renin angiotensin aldosterone system (RAAS). The consequence of LV hypertrophy is increased chamber-stiffness and delayed active LV relaxation which initially will cause diastolic and later systolic dysfunction. In heart failure (HF) and ischemic heart disease the degree of diastolic dysfunction has been demonstrated to correlate with functional class, neurohormonal activation and prognosis which also recently have been suggested for AVS. With longstanding elevated filling pressures the left atrium (LA) will dilate. Only limited data are available on the degree and importance of LA dilatation in AVS. When apparent, symptoms of HF in AVS are associated with high mortality rates. If LV systolic dysfunction also is present prognosis will deteriorate further. In these cases aorta valve replacement (AVR) is recommended. AVR will normalize pressure overload and thereby decreases LV hypertrophy. Previously it was believed that in time LV hypertrophy regressed towards normal and even normalized. Recent studies however have demonstrated that LV hypertrophy regression mainly happens during the first year after AVR, and little subsequent changes are seen during the remaining 10 years. Furthermore, patients that experience most regression of hypertrophy have more favourable outcome and better functional class than patients with less regression of hypertrophy. Thus absence of reverse remodelling is associated with poor outcome after AVR. Importantly the regression of LV hypertrophy is closely paralleled by decreasing RAAS hyperactivity. RAAS hyperactivity may be attenuated pharmacologically with angiotensin II receptor blockers (ARB) which in systemic hypertension with LV hypertrophy has been associated with reverse remodelling. The hypothesis is that in patients undergoing AVR for symptomatic AVS, 12 months post operative blockade of the angiotensin II receptor will accelerate LV and LA reverse remodelling, reduce filling pressures and suppress neurohormonal activation compared with conventional therapy. This will lead to improved exercise tolerance and due to improved left atrial function reducing the risk of atrial arrythmias.

To improve diagnostic methods for patients with laryngeal stenosis for the optimal determination of the technique of surgical treatment.

Optimize a candidate software algorithm using data collected with the Vivio system for use as an aid in the identification of heart sounds associated with severe aortic stenosis