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Johns Hopkins Symptoms and Remedies

Johns Hopkins Medicine

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Renal Artery Stenosis

What is it?

Renal artery stenosis is a blockage of one of the arteries that supply blood to the kidneys.When the renal artery or one of its branches is blocked, the blood supply to the kidney is partially or completely cut off; the affected kidney tissue may be damaged irreversibly. The unaffected kidney compensates for the decrease in function of the other one.Often, renal artery stenosis has no symptoms. Its most common indication is high blood pressure that responds poorly to regular treatment measures. Although chronic kidney failure may be a possibility if both kidneys are affected (or if someone has only one kidney), in many cases blockage may be reduced or eliminated with treatment, and kidney function may stabilize or improve.

What Causes It?

  • Buildup of plaque in the arteries (atherosclerosis) is the most common cause of renal artery stenosis.
  • An inherited disorder called fibromuscular dysplasia causes abnormal thickening of the arterial walls and may thus block the renal artery. This disorder primarily affects women between ages 20 and 40.

Prevention

  • Maintaining a healthy weight, diet, and lifestyle, including avoiding smoking, to prevent the buildup of plaque in the arteries may help to prevent renal artery stenosis.

Diagnosis

  • Patient history and physical examination.
  • Urine and blood samples.
  • Renal artery stenosis is suspected when blood pressure is unusually high, particularly hard to control, starts late in life, or rises suddenly in a person with previously normal blood pressure. Under such circumstances the tests described below may be done.
  • Renal arteriography allows the exact location of the blockage to be determined.
  • Ultrasound, CT (computed tomography) scans, or MRA (magnetic resonance of angiography) may be done.

How to Treat It

  • Percutaneous transluminal angioplasty, in which a tiny balloon on the tip of a catheter is threaded through the artery, may be performed. At the narrowed or blocked point, the balloon is inflated to widen the passageway. If this fails, the radiologist may insert a stent (a hollow rodlike device) at the location of the blockage to help keep the artery open.
  • Antihypertensive drugs may be needed to lower associated high blood pressure.
  • Surgery may be performed to remove or bypass an extensive or calcified (hardened) blockage. In cases of severe arterial wall damage, tissue from an artery elsewhere in the body is grafted onto the renal artery.
  • Cholesterol-lowering drugs may be prescribed.

When to Call a Doctor

  • Call a doctor immediately if you notice a decrease in urine output (an indication of kidney failure) or if you develop lower back pain accompanied by nausea, vomiting, and possibly fever (indications of kidney tissue death due to sudden blockage of a renal artery).