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

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 (high blood pressure) 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 valve 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.

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

An abrupt decrease in urine output (if patient has a single kidney)

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

The doctor will likely not be able to identify the problem by simply examining the patient, unless the disorder has persisted long enough to cause kidney failure.

• An MRI or renal scan shows lack of blood flow to the affected kidney.
• Renal arteriography will show the exact location of the occlusion.