Active clinical trials for "Constriction, Pathologic"

Aortic stenosis is the most common heart valve disease requiring intervention in high income countries. It is characterised by progressive valvular thickening, and restriction as well is hypertrophy and fibrosis of the left ventricle in response to pressure overload. The pathological processes in the left ventricle that ultimately result in heart failure and death are incompletely understood. Further elucidation of these processes and how they correlate with novel blood biomarkers may help us design new treatments and optimise the timing of surgical intervention. In brief, recruited patients with severe aortic stenosis and scheduled to undergo valve replacement surgery will be invited for some simple tests (blood sampling, ECG, echocardiogram). A septal myocardial biopsy will be taken at the time of surgery and the disease valve retained. These will be examined histologically and pathological changes compared with results obtained from ECG, echocardiogram and blood tests.

Calcified aortic stenosis is the most frequent valvulopathy in Europe and North America. Aortic stenosis is an obstacle to the ejection of blood from the left ventricle to the aorta and leads to morphological changes in the left ventricle and hemodynamic modifications. Intrinsic ventricular performance can be characterized using three parameters: Ventricular elastance (Ees for End Systolic Elastance) which represents the index of ventricular contractility independently of the load. Arterial elastance (Ea for Arterial Elastance) which represents the post-load The ventriculo-arterial coupling index (Ees / Ea) which represents energy efficiency. For patients with high surgical risk (EuroSCORE II> 6), TAVI (Transcatheter Aortic Valve Implantation) is recommended for aortic valve replacement. Many complications may occur after TAVI (haemorrhagic, embolic, renal, myocardial ischemia). Post-TAVI complications may also be cardiac decompensation of the underlying cardiac disease to cardiogenic shock. However, literature on left ventricular performance after aortic valvular replacement is poor because of the difficulty and invasiveness of the analysis involved. Cardiac energy analysis plays an additional role in understanding the clinical patients conditions. On this point, cardiac energy modifications, based on ventriculo-arterial coupling, could be indicators of cardiac function. Two methods (ultrasound and pulse contour) are used to understand and explore the ventriculo-arterial coupling, preload, postload, contractility and hemodynamic changes interactions. Echocardiography allows the Ees / Ea and SW / PVA (Stoke work/ pressure-volume area) ratios mesurements. PRAM (Pressure Recording Analytical Method) through the MostCare® monitor, gives common hemodynamic parameters and more specific parameters such as arterial elastance (Ea) cardiac cycle efficiency (CCE), dP / dt. Cardiac cycle efficiency (CCE) is an exclusive variable that describes the hemodynamic performance in terms of energy expenditure in the patient being followed. TAVI procedure is an acute model of ventriculo-arterial coupling modification by treatment of the ventricular ejection obstacle. The PRAM method evaluates the ventriculo-arterial coupling. The aim of our study is to evaluate by PRAM the changes in cardiac energy variables before and after aortic valve replacement by TAVI

Stroke has become the leading cause of death in China. It has been shown that intracranial artery stenosis (ICAS) plays a key role in Chinese stroke patients. Although most of stenotic diseases in intracranial arteries are atherosclerotic, a substantial number of other vascular diseases, such as dissection, arteritis, moyamoya disease, and reversible cerebral vasoconstriction syndrome (RCVS), can also lead to intracranial artery luminal narrowing. It is challenging to differentiate the etiologies of ICAS relying on measuring luminal narrowing by angiographical approaches. In addition, the progression of intracranial atherosclerotic disease (ICAD) has been demonstrated to be highly associated with the risk of ischemic cerebrovascular events. However, the influence factors for ICAD progression remains unclear. High-resolution magnetic resonance imaging (HR-MRI) has been widely used to assess ICAS diseases. The different etiologies of ICAS are differentiable by MR-MRI according to the features of location, shape, signal pattern, remodeling, and contrast enhancement. Investigators have proved that HR-MRI is a reproducible technique that may be reliably utilized to monitor the changes of ICAD during natural follow-up or medical treatment. The ICASMAP (Intracranial Artery Stenosis MR Imaging: Aetiology and Progression) is a prospective, cross-sectional, observational, and multicenter study. The objectives of ICASMAP are to determine: 1) the spectrum of etiology of ICAS in stroke patients; and 2) the influence factors for progression of ICAD. A total of 300 patients with symptomatic stenotic disease in intracranial arteries (stenosis range: 30%-99%) will be recruited within two weeks after symptom onset from 18 different hospitals across Beijing-Tianjin-Hebei region in China within 1 year. All the patients will undergo HR-MRI for intracranial arteries at baseline, one-year, and two-years. The clinical risk factors will be collected and blood draw will be conducted. The ICASMAP study may help to improve the precise diagnosis and intervention of ICAS and stroke prevention.

The study will consist of two parts: In Study A, objectively assessed physical activity, gait, balance, range of movement of specific joints during walking and neurophysiological findings between patients with cervical spine stenosis (CSS) without myelopathy who will be treated conservatively and patients with stenosis and signs of myelopathy who are candidates for surgical Treatment will be compared. In Study B, the 6-month changes in the same outcomes in patients treated conservatively (from the first specialist consultation until 6 months later) and in patients treated surgically (preoperative day and 6-month post-operatively) will be quantified.

In this feasibility study (non-randomized), the applicability of a new "moving cell" biliary stents (by HILZO) in Klatskin tumors (bile duct obstruction) will be investigated. The HILZO Moving-Cell Stent to be examined here is a non-coated metal stent with a novelty. The meshes have a diameter of 4 mm, which is rather small compared to most other stents. This significantly increases the radial force and thus the stability of the stent. Furthermore, ingrowth by tumors in the stent is difficult. The special feature is that the individual meshes can easily be stretched to 10 mm without changing the stability of the stent. This allows a second stent to pass through the first to another segment of liver.

The aim of this retrospective, multicenter study is to demonstrate that the use of EndoNaut for aortoiliac endovascular procedures has a clinical impact for the patient (reduction in irradiation and the volume of contrast product) as well as for the nursing staff (reduction irradiation) compared to procedures performed without EndoNaut.

The investigators will retrospectively study lumbar spinal stenosis patients who underwent OLIF or MIS-TLIF with percutaneous pedicle screw fixation between January 2016 and December 2019.The investigators will measure estimated blood loss, operative time, hospital stay, cost, reoperation, and complication incidence, visual analogue scale (VAS), Oswestry Disability Index (ODI), Japanese Orthopaedic Association (JOA), and Short Form-36 (SF-36) scores, discal and foraminal height, lumbar lordotic angle, and fusion status.The investigators will conduct to evaluate postoperative improvements, complications, and reoperation rates between patients with lumbar spinal stenosis (LSS) undergoing oblique lateral interbody fusion (OLIF) or minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF).

The correlation between metabolic syndrome and carotid artery stenosis is well established. The purpose of this study is to evaluate the relationship between morbid obesity and carotid artery stenosis.

Aortic stenosis (AS) is the most common valvular heart disease. Once symptomatic with severe AS, outcome is poor unless the valve is replaced surgically or via transcatheter aortic valve replacement (TAVR). Transthyretin amyloid (ATTR) deposits are common in the heart muscle in up to 25% of octogenarians, and after an asymptomatic period of unknown duration, cause overt heart failure and arrhythmias in a proportion of cases. The prevalence and impact of covert ATTR amyloidosis in elderly individuals with AS are unknown. Detection would avoid misdiagnosis, guide treatment and, potentially, improve outcomes. Recent data have shown that echocardiography, cardiovascular magnetic resonance (CMR), computed tomography (CT), and DPD scintigraphy, can identify ATTR amyloid deposits, but the clinical performance of these various tests is unknown. This study will investigate elderly patients with symptomatic severe AS using imaging to explore ATTR amyloid in AS and determine its prevalence and impact on outcome. The investigators aim to recruit a total of 250 patients aged 75 or older being considered for intervention for severe AS. The prevalence of cardiac amyloid will be assessed in three arms (sAVR, TAVI and medical therapy, with a likely patient ratio of 50:150:50), using five investigation modalities - all cohorts (echocardiography and DPD scintigraphy); sAVR cohort (biopsy and CMR); TAVI cohort (EqCT); medical therapy only cohort (as per work-up/trial prior to no intervention decision). The primary outcome measure is patient mortality. Secondary outcomes measures are major adverse cardiovascular events, length of stay, pacemaker implantation, ECV measured by EqCT and CMR. Follow up will be at 1-year with clinical echocardiogram (for sAVR and TAVI patients) and/or telephone interview for all patients (if not carried out in person at the time of the echocardiogram).

Purpose of the study To evaluate the lower puntum dimensions in cases of acquired punctal stenosis(APS), using anterior segment optical coherence tomography (AS-OCT).