Alternative names
Acute arterial occlusion - kidney; Renal artery embolism; Acute renal artery occlusion; Embolism - renal artery

Definition
Acute renal arterial thrombosis is a sudden, severe blockage of the artery that supplies the kidney.

Causes, incidence, and risk factors

The kidneys are very sensitive to the amount of blood that flows through them. Any reduction of blood flow through the renal artery can impair kidney function. If prolonged, a complete blockage of blood flow to the kidney often results in permanent failure of the kidney.

Lack of functioning of one kidney may not cause symptoms because the second kidney adequately filters the blood. Hypertension may develop, however. If there is not a second functional kidney, blockage of the renal artery may cause symptoms of acute kidney failure.

Acute arterial occlusion of the kidney may occur after injury or trauma to the abdomen, side, or occasionally the back. Emboli (blood clots that travel through the blood stream) may lodge in the renal artery.

The risk of emboli increases if there is a history of certain heart disorders such as mitral stenosis or atrial fibrillation. Individuals with disorders that make them highly likely to form clots may be particularly vulnerable to acute renal artery occlusions.

Occasionally, renal artery stenosis may increase the risk of a sudden occlusion due to clot formation.

Symptoms

 
• Flank pain or pain in the side, not colicky or spasmodic  
• Abdominal pain  
• Back pain  
• Blood in the urine

Note: There may be no pain. Pain, if present, usually develops suddenly.

Signs and tests
Physical examination is generally unrevealing unless the disorder has persisted long enough to cause kidney failure.

 
• Kidney ultrasound is the initial diagnostic test of choice to identify renal artery occlusions.  
• An IVP (intravenous pyelogram) may show no function of the affected kidney.  
• A renal scan may indicate lack of blood flow to the affected kidney.  
• Renal arteriography will show the exact location of the occlusion.

This disease may also alter the results of an abdominal MRI.

Treatment
Often, no specific treatment is recommended. Blood clots may resolve spontaneously in time.

If the blockage is discovered within a few hours of its occurrence, or if the affected kidney is the only functional kidney, attempts may be made to open the artery.

Attempts to open the artery may include use of clot-dissolving medications (thrombolytics) and medications that prevent the blood from clotting (anticoagulants) such as Coumadin.

Surgical repair of the artery or removal of the blockage with a catheter inserted into the artery by a radiologist may be required in some cases.

Treatment for acute renal failure may be appropriate.

Expectations (prognosis)
If only one kidney is affected, the healthy kidney may take over filtering and urine production. Damage caused by arterial occlusion may be temporary, but it is usually permanent. If there is only one functional kidney, arterial occlusion results in acute renal failure that often persists as chronic renal failure.

Complications

 
• Hypertension  
• Malignant hypertension  
• Acute renal failure  
• Renal artery stenosis  
• Chronic renal failure  
• End-stage renal disease

Calling your health care provider
Call your health care provider if urine production stops, or if sudden, severe pain occurs in the back, flank, or abdomen.

If you have only one functional kidney and symptoms of acute arterial occlusion appear, go to the emergency room or call the local emergency number such as 911.

Prevention
In many cases the disorder is not preventable. The most important way to reduce risk is to stop smoking.

Preventive use of anticoagulants may be recommended for people with a high risk of developing emboli such as those with mitral stenosis, atrial fibrillation, or coagulation disorders. Control of atherosclerotic disease may reduce risk.

Medical Encyclopedia

All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.