Active clinical trials for "Constriction, Pathologic"

Although concomitant coronary artery disease (CAD) is frequent in patients with severe aortic stenosis (AS), hemodynamic assessment of CAD severity in patients undergoing valve replacement for severe AS is challenging. Myocardial hypertrophic remodeling interferes with coronary blood flow and may influence the values of fractional flow reserve (FFR) and nonhyperemic pressure ratios (NHPRs). The aim of the current study is to investigate the effect of the AS and its treatment on current indices used for evaluation of CAD. The investigators will compare intracoronary hemodynamics before, immediately after, and 6 mo after aortic valve replacement (AVR) when it is expected that microvascular function has improved. Furthermore, the investigators will compare FFR and resting full-cycle ratio (RFR) with myocardial perfusion single-photon emission-computed tomography (SPECT) as indicators of myocardial ischemia in patients with AS and CAD. One-hundred consecutive patients with AS and intermediate CAD will be prospectively included. Patients will undergo pre-AVR SPECT and intracoronary hemodynamic assessment at baseline, immediately after valve replacement [if transcatheter AVR (TAVR) is chosen], and 6 mo after AVR. The primary end point is the change in FFR 6 mo after AVR. Secondary end points include the acute change of FFR after TAVR, the diagnostic accuracy of FFR versus RFR compared with SPECT for the assessment of ischemia, changes in microvascular function as assessed by the index of microcirculatory resistance (IMR), and the effect of these changes on FFR. The present study will evaluate intracoronary hemodynamic parameters before, immediately after, and 6 mo after AVR in patients with AS and intermediate coronary stenosis. The understanding of the impact of AVR on the assessment of FFR, NHPR, and microvascular function may help guide the need for revascularization in patients with AS and CAD planned for AVR.

The study objective is to evaluate safety and effectiveness/performance of the Microport™ CardioFlow VitaFlow™ Transcatheter Aortic Valve System for the treatment of severe aortic stenosis in the real world settings.

Degenerative cervical kyphosis with stenosis (DCKS) is a common cervical spine degenerative disease, causing pain, numbness, and weakness of limbs, which seriously affect the quality of life of the patient. Surgery is an effective way to treat this condition, however, the best surgical procedure is still controversial. Anterior spinal canal reconstruction and fusion surgery (ACRF) is a new surgical procedure that previously proposed by our team, it combines the advantages of both the conventional anterior and posterior approach. The purpose of this study is to evaluate the safety and effectiveness of ACRF surgery for treating DCKS. A multicenter prospective randomized controlled trial was designed. Eligible patients will be randomly divided into three groups, including the ACRF group, the conventional anterior surgery group, and the conventional posterior surgery group. Demographic data, surgery Information, and follow-up results will be collected and compared between groups.

Myval European Study: A retrospective, multicentre, observational study in patients presenting with native severe aortic valve stenosis and treated with Myval™ Transcatheter Heart Valve System in real-world setting.

The transparent cap-assisted endoscope has the function of fixing field of view and increasing visual space. It has been widely used in gastrointestinal examination and treatment. In this study, the investigators intend to apply transparent cap-assisted choledochoscopy to endoscopic biliary tract exploration and biopsy to investigate whether transparent cap-assisted choledochoscopy can improve operability, visual field clarity, and biopsy accuracy.

The EMPIRE II study evaluates the safety and performance of the entire ALLEGRA THV System. The primary safety endpoint is composite of all-cause mortality or stroke rates at 12 months. And the primary performance endpoint is device success at 7 days. Based on the outcomes of a study with a similar device and considering a drop-out rate of 5%, 177 patients need to be enrolled in the study.

The purpose of this study is to assess the impact of temperature-sensitive radiofrequency ablation (RFA) immediately before biliary stent placement on duration of biliary stent patency and re-intervention free survival. This is a research study meant to collect information to help other patients with malignant biliary strictures in the future.

This study is to improve the understanding of the role of postural and ambulatory biomechanics for symptoms in patients with sLSS and to correlate patient-reported outcome measures (PROMs) with dynamic compensation (difference between static and dynamic sagittal spinal alignment) in patients with symptomatic lumbar spinal stenosis sLSS).

Collect data on the safety and clinical performance of the Braile Biomédica® Bovine Pericardium Valvular Bioprosthesis

The field of research for this study is tissue engineering and the utilization of a bioengineered collagen implant as a substitute biomaterial for conventional buccal mucosa in substitution urethroplasty of distal urethral strictures.