Saturday, May 14, 2011

Renal Artery Stenosis

Renal artery stenosis is the narrowing of one of the arteries that supply oxygen-rich blood to the kidneys. Since this constriction of the renal artery can hinder the blood flow that target the kidney, renal artery stenosis may result in hypertension, atrophy of the affected kidney, and renal failure if not treated. Atherosclerosis is the predominant cause of renal artery stenosis in the majority of patients, usually those with a sudden onset of hypertension at age 50 or older. Fibromuscular dysplasia is the predominant cause in young patients, usually females under 40 years of age. A variety of other causes exist. These include arteritis, renal artery aneurysm, extrinsic compression, neurofibromatosis, and fibrous bands.

Renal artery stenosis (RAS) can cause high blood pressure and reduce kidney function. It is often overlooked as a cause of high blood pressure. Most cases of renal artery stenosis are asymptomatic, and the main problem is high blood pressure that cannot be controlled with medication. Deterioration in renal function may develop if both kidneys are poorly supplied, or when treatment with an ACE inhibitor is initiated.

Renal artery stenosis is initially treated with medications. These include statins, antiplatelet agents and drugs for control of blood pressure. When high-grade renal artery stenosis is documented and blood pressure cannot be controlled with medication, or if renal function deteriorates, invasive procedure may be resorted to. The most commonly used invasive procedure is angioplasty with or without stenting. A 2003 meta-analysis found that angioplasty was safe and effective in this contex.

Bilateral Renal Artery Stenosis