Active clinical trials for "Renal Artery Obstruction"

Subjects referred for a routine CTA (computed tomography angiography) or MRA (magnetic resonance angiography) will be invited to participate in the study and subjects will be involved in the study for between 2 and 12 days. Two to three visits to the study doctor will be required. This study will compare the diagnostic results of Gadobutrol enhanced MRA images with MRA images taken without contrast agent using images from a CTA as the standard of reference, which may have been performed up to 60 days prior to enrolment. If a CTA has not been performed in this prior time period, a CTA is required for the study. MRA and CTA images will be collected for an independent review (blinded read).

Renal transplantation is the standard treatment for patients with end-stage chronic kidney disease because it is effective in reducing the morbidity and mortality. Despite of the satisfactory results, some patients evolve with graft dysfunction and refractory hypertension due to transplanted renal artery stenosis (TRAS). TRAS is the main vascular complication of patients undergoing kidney transplantation, with a reported incidence ranging 1 to 23% in the different series in the literature, depending on the definition and diagnostic techniques used, manifesting most commonly between the 3rd month and the 2nd year after transplantation. Percutaneous intervention of TRAS is widely accepted as a viable treatment option, but there are few long-term data on patients undergoing angioplasty. The aim of this study was to evaluate long term outcomes clinical in patients with TRAS underwent to percutaneous intervention with or without stent.

The anastomotic and peripheral stenosis of the transplanted kidney artery is one of the most important causes of graft failure in renal transplantation. The injury of vascular intima and the formation of microthrombosis may play a significant role in the stenosis of transplanted renal artery of recipients. Inhibiting this process with aspirin may protects against the stenosis of transplanted renal artery. This is a prospective, randomized, controlled, clinical trial to investigate the efficacy and safety of prevention of renal artery stenosis in recipients.

This study will compare the results of a clinically ordered abdominal CT angiography to a research non-contrast MR angiogram (MRA). CTA is a "gold-standard" for identifying blockages in the kidney arteries or other blood vessel problems. CTA requires radiation and contrast to obtain useful images. Conversely, the MR abdomen technique being used for the study uses no radiation or contrast and is felt to be a safer option for individuals who have kidney problems. there is benefit to establishing non-contrast MRA as a clinically accurate test.

Atherosclerotic renal artery stenosis (ARAS) is associated with progressive loss of renal function, refractory hypertension and flushing edema, responsible for mortality and morbidity, especially in the elderly. Current treatment includes restoration of the renal arterial lumen by endovascular stent placement and/or intensive medical therapy. There is no unanimous consent on which patients could benefice of the endovascular procedure due to the high rate of renal adverse events especially linked to atheroembolic disease. Recently, renal revascularization using a device which consents distal embolic protection of the kidney demonstrated to be a "safe" auxiliary procedure in a few non randomized studies. Interestingly atheromatous debris was detected in 60 to 80% of these devices analyzed after the procedure suggesting that these devices could prevent atheroembolism in a substantial proportion of patients. On the other hand, only a randomized controlled study can prove that renal stent with distal embolic protection is superior to renal stent alone in preserving kidney function. Therefore, the present study aims to compare the effects of renal artery stent placement with or without distal embolic protection on renal function in ARAS patients. Method: Patients with an ARAS of ≥70% and hypertension not responsive to at least 2 antihypertensive medications and/or renal failure (estimated GFR <60 mL/min/1.73 m2 are randomly assigned to stent placement alone or stent placement with distal embolic protection (FILTER WIRE EX; Cordis Endovascular, USA). Other medications consist of statins, anti-hypertensive drugs and antiplatelet therapy. Patients are followed for 3 months. The primary outcome of this study is a statistical significant difference in kidney function measured as Cr clearance and cystatin C level in the 2 groups at three months. The trial will include 150 patients.

The investigators conducted a bicentric prospective study to quantify the hemodynamic disturbances to the ostia of the renal arteries generated by the implantation EVAR with suprarenal fixation immediately postoperatively.

Stenosis of the renal graft arteries occurs in 1 to 26% of cases and can damage the graft. Endovascular treatment is first-line treatment. The main objective of this study is to identify the predictive factors of failure of peri-anastomotic.

All patients referred for coronary angiography will simultaneously be evaluated for renal artery stenosis and then stenosis more than 50% will be analyzed according to clinical conditions, risk factors and lab data.

Fibromuscular dysplasia (FMD) is localized structural defects in the arterial wall, whose innate or acquired character is still unknown. This segmental non atheromatous injury, leads to stenosis of the arteries of small and medium caliber. Renal arteries are the most commonly affected with 60-75% of total fibrodysplasia. Three histological subtypes have been described: intimal, medial and peri-medial. They are not mutually exclusive and can be observed in the same patient. This is a rare blood disease, occurring in children and young adults. In this young population with long life expectancy, these aneurysmal lesion are associated with 10% risk of rupture. To date, no data have shown in the literature that FMD is link to genetic causes, or if there is specific histopathologic lesions for non-atherosclerotic renal artery aneurysms. To answer these questions, Cardiovascular Surgery Unit of the University Hospital of Saint-Etienne, French national reference center for renal artery surgery, in association with the Reference Center for Rare Vascular Disease in Paris, designed the first study for pathological and genetic characteristics of dysplastic renal artery aneurysms in young patients.

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.