Atheroembolic renal disease

Definition

Atheroembolic renal disease (AERD) is an inflammatory reaction in the small blood vessels of the kidneys.

Alternative Names

Renal disease - atheroembolic; Cholesterol embolization syndrome; Atheroemboli - renal; Atherosclerotic disease - renal

Causes, incidence, and risk factors

AERD is linked to atherosclerosis. Atherosclerosis is a common disorder of the arteries. It occurs when fat, cholesterol, and other substances build up in the walls of arteries and form hard substances called plaque.

In AERD, cholesterol crystals break off from the plaque lining the arteries. These crystals move into the blood stream. Once in circulation, the crystals get stuck in tiny blood vessels called arterioles. There, they cause intense swelling and pain that can harm the kidney or other parts of the body

The result is organ damage due to decreased blood supply. The kidneys are involved about half the tiome. Other body parts that may be involved include the skin, eyes, muscles and bones, brain and nerves, and organs in the abdomen. Acute kidney failure is possible if the reaction is severe.

Atherosclerosis of the aorta is the most common cause of AERD. The cholesterol crystals may also break off during aortic angiography, cardiac catheterization or surgery of the aorta or other major arteries.

In some cases, AERD may occur without a known cause.

The risk factors for AERD are the same as risk factors for atherosclerosis.

Symptoms

AERD may not cause any symptoms. If there are symptoms, they may begin suddenly, or slowly get worse over weeks or even months. Symptoms may include:

• Fever, muscle aches, headaches, and weight loss
• Flank (sides of the body) pain and blood in the urine (rare)
• Foot pain, ulcers on the feet, or “blue toes”
• High blood pressure that is difficult to control
• Pain in the abdomen, nausea, or vomiting
• Pancreatitis or hepatitis (rare)
• Strokes or blindness

Kidney failure may result in:

• Decrease in sensation (feeling)
• Decreased or no urine output
• Drowsiness, confusion, lethargy
• Dry itchy skin
• Loss of appetite
• Nausea or vomiting
• Skin pigment changes
• Swelling
• Weight loss

Signs and tests

The doctor will perform a physical exam. Swelling may affect the entire body. An eye exam may show particles in the small arteries of the retina.

The doctor will listen to your lungs and heart with a stethoscope. Abnormal sounds may be heard. For example, a loud whooshing sound called a bruit may be heard over the aorta or renal artery.

Blood pressure may be high. There may be multiple ulcers of the skin of the lower feet.

Tests that may be done include:

• Abdominal CT scan
• Abdominal MRI
• Abdominal x-ray
• Chem-7 or chem-20
• Complete blood count
• Kidney biopsy
• Kidney function tests including BUN and creatinine
• Kidney or abdominal ultrasound
• Renal arteriography
• Serum complement
• Serum lipids
• Urinalysis

Treatment

There is no treatment for artheroembolic renal disease that works well. Treatment is focused on managing the complications.

Medicines may be used to treat high blood pressure and lower lipid and cholesterol levels.

• Your doctor may tell you to reduce fats and cholesterol in your diet.
• Other treatments for kidney failure or complications may be needed. If you have kidney failure, you may need to restrict protein, salt, and fluids, or make other dietary changes. See Chronic renal failure and End-stage kidney disease.

Your doctor may also recommend other lifestyle changes such as increased exercise or weight loss. Stopping smoking is extremely important.

Expectations (prognosis)

The outcome varies but is generally poor. The disorder slowly gets worse over time. Lifestyle changes may help slow progression of the disease.

Complications

• Acute renal failure
• Blood clots to other location of the body -- brain, intestine, legs
• Chronic renal failure
• High blood pressure

Calling your health care provider

Call your doctor if you have:

• A decrease in urine output or no urine production
• Blood in the urine
• Severe abdominal pain or leg pain
• Toes that turn purple and occur with foot pain
• Unexplained ulcers on your legs or feet

Prevention

You can alter the factors that increase your risk of getting this disease. You should lose weight if you are obese, decrease or stop smoking, and follow your doctor's recommendations to control diabetes or high blood pressure. Reducing fats, especially saturated fats, in your diet may help to reduce serum lipid levels.

References

Kanso AA, Hassan NMA, Badr KF. Microvascular and macrovascular diseases of the kidney. In: Brenner BM, ed. Brenner and Rector's The Kidney. 8th ed. Philadelphia, Pa; Saunders Elsevier; 2007: chap 32.