View clinical trials related to Renal Artery Obstruction.
Filter by:Magnetic Resonance Angiography (MRA) is an examination similar to Magnetic Resonance Imaging (MRI) which uses a magnetic field and a contrast medium when needed to visualize blood flow in the arterial vessels throughout the body. Gadodiamide, a contrast medium, is already approved and is used to image blood vessels by directly injecting it into the vein, but this procedure has not been formally tested to image the renal artery vessels using MR. The study is designed to determine the presence or absence of a relevant stenosis (ie greater than/equal to 50%) or occlusion in renal arteries. Intra-arterial Digital Subtraction Angiography will be used as the standard of truth.
The purpose of this study is to evaluate the safety and effectiveness of the RX HERCULINK 14 Peripheral Stent System in treating atherosclerotic renal artery stenosis.
Background: Atherosclerotic renal artery stenosis (ARAS) is associated with progressive loss of renal function and is one of the most important causes of renal failure in the elderly. Current treatment includes restoration of the renal arterial lumen by endovascular stent placement. However, this treatment only affects damage caused by ARAS due to the stenosis and ensuing post-stenotic ischemia. ARAS patients have severe general vascular disease. Atherosclerosis and hypertension can also damage the kidney parenchyma causing renal failure. Medical treatment focuses on the latter. Lipidlowering drugs (statins) could reduce renal failure progression and could reduce the overall high cardiovascular risk. The additional effect on preserving renal function of stent placement as compared to medical therapy alone is unknown. Therefore, the STAR-study aims to compare the effects of renal artery stent placement together with medication vs. medication alone on renal function in ARAS patients. Method: Patients with an ARAS of ≥50% and renal failure (creatinine (Cr) clearance <80 mL/min/1.73 m2) are randomly assigned to stent placement with medication or to medication alone. Medication consists of statins, anti-hypertensive drugs and antiplatelet therapy. Patients are followed for 2 yrs with extended follow-up to 5 yrs. The primary outcome of this study is a reduction in Cr clearance >20% compared to baseline. This trial will include 140 patients.
This study will compare medical therapy plus stenting of hemodynamically significant renal artery stenoses versus medical therapy alone in patients with systolic hypertension and renal artery stenosis.
This study will use magnetic resonance imaging (MRI) to picture the kidney and renal arteries (arteries that supply blood to the kidney) in patients scheduled for kidney artery angiogram and angioplasty/stenting procedures. An angiogram is a way of taking pictures of arteries that shows areas of narrowing caused by atherosclerosis-a buildup of plaque on the vessel wall. Angioplasty/stent is a treatment procedure in which a balloon-tipped catheter is inserted in the artery and advanced to the area of blockage to open the vessel, increasing blood flow to the kidney. A permanent metal tube (stent) may or may not be put in place to maintain the opening. During either of these invasive procedures, small pieces of plaque can break off and travel in the blood to lodge elsewhere in the body. This is called embolization. Lodged in the kidney, the embolus can impair kidney function. Currently, these emboli cannot be detected. A new way of visualizing the kidneys that allows detection of emboli may reveal whether material has moved to the kidneys and predict if there will be any kidney damage. Patients 21 years of age and older with suspected kidney artery disease scheduled for invasive angiographic evaluation in NIH protocol 95-H-0047 may be eligible for this study. Participants will be assigned to one of two study groups, based on the angiogram findings and the decision to have the angioplasty/stent procedure. Participants in both groups will have baseline MRI scans up to 2 weeks before the invasive procedure (angiogram with or without angioplasty/stent) and again within a day after the procedure. Patients who undergo angioplasty/stent will have another MRI study within about a month following the procedure. MRI uses a magnetic field and radio waves to produce images of body tissues. The patient lies on a table that slides into a large hollow tube (the scanner). During part of the scan, a material called gadolinium contrast may be injected into a vein. This substance brightens the images to better show the kidneys, their blood vessels and blood flow. The procedure lasts from about 1 to 2 hours. During the MRI, the heart is monitored with an electrocardiogram (EKG) and breathing is monitored with a flexible belt. Blood pressure is measured intermittently. The patient can communicate with a staff member at all times. Blood samples will be drawn from an arm vein at the initial clinic visit, within a day after the procedure and about 1 week after the procedure. For patients who had the angioplasty/stent procedure, a third blood sample will be taken within another 6 six weeks. The blood samples will be used to check for changes in kidney function.
In this study researchers will admit and evaluate patients with known or suspected heart disease referred to the Cardiology Branch of the National Heart, Lung, and Blood Institute (NHLBI). Patients participating in this study will undergo a general medical evaluation, including blood tests, urine, examination, chest x-ray and electrocardiogram (EKG). In addition, patients may be asked to have an echocardiogram (ultrasound scan of the heart) and to perform an exercise stress test. These tests are designed to assess the types and causes of patient's heart diseases and to determine if they can participate in other, specific research studies.