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Renal artery stenosis Causes and Risks:
Renal artery stenosis is caused when atheroembolic renal disease results in narrowing of the renal artery. A second cause is fibromuscular disease, a condition more common in young women in which fibrous tissue grows in the wall of the renal artery and narrows it. It may also be caused when scar tissue forms in the renal artery after acute arterial obstruction or traumatic injury to the kidney.
Renal artery stenosis often causes hypertension with no other signs of its presence and is usually discovered in investigation for the cause of hypertension that is difficult to control. In fact, renal artery stenosis accounts for 1 to 2% of all cases of hypertension. The disorder may also be discovered when a bruit (loud whooshing sound) over the kidney is noted on a routine examination or an examination of the abdomen for other disorders.
In the elderly, renal artery stenosis is most commonly associated with atherosclerotic disorders, including atherosclerotic heart disease . Atherosclerotic plaque deposits within the renal artery and causes it to become stenosed (narrowed). Fibromuscular dysplasia is a congenital disorder involving thickening of the arterial wall and is a cause of renal artery stenosis in younger adults, particularly women 20 to 40 years old.
Renal artery stenosis may cause chronic renal failure .
Prevention:
The prevention is to avoid smoking .
Symptoms:
There are usually no symptoms.
Signs and Tests:
The blood pressure may be high, and there may be a history of hypertension that is refractory or difficult to control. A bruit may be heard on examination with a stethoscope ( auscultation ) over the kidney.
- A radionuclide cystogram may indicate a decreased blood flow. The value of radionuclide scanning is increased if the test is done twice: once after a dose of captopril and once without the captopril.
- A kidney X-ray , kidney CT scan, or kidney ultrasound may indicate a decreased size of the kidney, and/or a decreased arterial flow secondary to narrowing of the artery.
- Renal arteriography shows the exact location of the stenosed area.
This disease may also alter the results of the following tests:
Treatment:
The treatment varies depending on the extent and severity of the symptoms. The second kidney may take over filtering and urine production for the body if the stenosis results in failure of that kidney. Surgical repair of the stenosed area may be possible. A balloon angioplasty (a radiographic procedure during which a balloon-tipped catheter is threaded through the artery) may be an alternative method of opening the stenosed area instead of surgery.
Antihypertensive medications may be needed to control high blood pressure .
Prognosis:
Renal artery stenosis may cause eventual failure of the kidney if it progressively blocks the artery. This may result in chronic renal failure if there is only one functional kidney or if both renal arteries are affected.
Renal hypertension caused by renal artery stenosis may be difficult to treat. Surgical or balloon catheter repair often successfully opens the stenosed area. However, stenosis may recur.
Complications:
Call Your Healthcare Provider:
If your history indicates a high risk for renal artery stenosis make an appointment to see your health care provider. However, decreased urine volume may be an emergency symptom indicating renal failure .
The kidneys are responsible for removing wastes from the body, regulating electrolyte balance and blood pressure, and the stimulation of red blood cell production. The gross anatomical structure of the kidney is illustrated.
This is the typical appearance of the blood vessels (vasculature) and urine flow pattern in the kidney. The blood vessels are shown in red and the urine flow pattern in yellow.
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