View clinical trials related to Constriction, Pathologic.
Filter by:Currently, aortic stenosis (AS) is considered a "surgical disease" with no medical therapy available to improve any clinical outcomes, including symptoms, time to surgery, or long-term survival. Thus far, randomized studies involving statins have not been promising with respect to slowing progressive valve stenosis. Beyond the valve, two common consequences of aortic stenosis are hypertrophic remodeling of the left ventricle (LV) and pulmonary venous hypertension; each of these has been associated with worse heart failure symptoms, increased operative mortality, and worse long-term outcomes. Whether altering LV structural abnormalities, improving LV function, and/or reducing pulmonary artery pressures with medical therapy would improve clinical outcomes in patients with AS has not been tested. Animal models of pressure overload have demonstrated that PDE5 inhibition influences NO-cGMP signaling in the LV and favorably impacts LV structure and function, but this has not been tested in humans with AS. Studies in humans with left-sided heart failure and pulmonary venous hypertension have shown that PDE5 inhibition improves functional capacity and quality of life, but patients with AS were not included in those studies. The investigators hypothesize that PDE5 inhibition with tadalafil will upregulate NO-cGMP signaling, reduce oxidative stress, and have a favorable impact on LV structure and function as well as pulmonary artery pressures and quality of life. In this pilot study, the investigators anticipate that short-term administration of tadalafil to patients with AS will be safe and well-tolerated.
The purpose of the study is to evaluate the safety and efficacy of the Medtronic CoreValve® System in the treatment of symptomatic severe aortic stenosis in subjects who have a predicted high risk for aortic valve surgery and/or very high risk for aortic valve surgery.
The purpose of this study is to study the evaluation of the use of metal stents as part of the treatment of benign biliary strictures.
The broad, long-term objective of this research protocol is to improve the quality of life for patients suffering from lumbar spinal stenosis. This objective will be met by examining the safety and clinical efficacy of epidural steroid injections for treatment of pain associated with lumbar spinal stenosis. This prospective, randomized, double-blind controlled trial (RCT) will test the hypothesis that the effectiveness of epidural steroid injections (ESI) plus local anesthetic (LA) is greater than epidural injections of LA alone in older adults with lumbar spinal stenosis.
The investigators are evaluating the use of a SpyBite biopsy forceps for tissue diagnosis when compared to standard biopsy techniques.
The current standard of care for benign bile duct strictures involves placement of multiple plastic stents under endoscopic and fluoroscopic guidance to progressively dilate or stretch it open. This approach necessitates multiple procedures which may extend over one year before the stricture is adequately dilated. The investigators propose a study comparing the standard approach of plastic stenting with the use of newer, fully coated metallic stents which are self-expandable, thereby permitting successful dilation of benign bile duct strictures with fewer procedures.
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.
Renal atherosclerotic stenosis (RAS) is a prevalent cause of secondary hypertension (HT). Since there are still uncertainties as to whether and in what patients revascularization by means of percutaneous renal angioplasty (PTRAS) should be pursued, we designed a study exploiting an optimized patient selection strategy and using hard experimental endpoints to unravel these uncertainties. Primary objective: to determine if revascularization by means of PTRAS is superior or equivalent to optimal medical treatment for preserving glomerular filtration rate in the ischemic kidney as assessed by 99mTcDTPA sequential renal scintiscan. Secondary objectives: to determine if the two treatments are equivalent in lowering blood pressure (BP), preserving overall renal function and regressing damage in the target organs of hypertension. Design: prospective multicenter randomized, unblinded two-arm study. Eligible patients will have clinical and/or radiological evidence of unilateral or bilateral RAS, defined by stenosis of the proximal portion of the renal artery and its main bifurcations at angioCT. Duplex scan will exclude nephroangiosclerosis as the latter could bias the assessment of the outcome of revascularization. Inclusion criteria. RAS affecting the main renal artery or its major branches at angio-CT either > 70% or, if < 70 with post-stenotic dilatation. Renal function will be assessed with 99mTc-DTPA renal scintigraphy. Sample size (30 patients per arm) was calculated to have a 90% power to detect a difference in means of GFR in the vascularized (or control untreated kidney) of 7.5 ml/min. Arms 1. Revascularization: digital scan angiography and PTA with stenting of the renal artery at the ostium or at truncular level, plus optimal medical therapy. 2. Medical therapy: the drug regimen that had been optimized during the run-in period. Experimental endpoints: The absolute value of GFR assessed by 99TcDTPA in the ischemic kidney will be used as quantitative variable and compared between groups at each time point. A categorical definition of kidney loss, defined as a GFR in the ischemic kidney of < 5 ml/min, will be also used and the rate of achievement of such endpoint will be compared. Duration: 5 years.
The primary objective of this study is to evaluate the safety and efficacy of transcatheter Cutting Balloon therapy for branch pulmonary artery stenosis resistant to low pressure dilation.
General and specific objectives of the search: evaluate the effects of the administration of Antithrombin III (ATIII) on the activation of the coagulation system and of the fibrinolysis, platelet function, inflammatory response and markers of organ damage in patients undergoing cardiac surgery by cardiopulmonary bypass (CPB) with low plasma levels of post-operative Antithrombin (AT).