Renal vein thrombosis

Blood clot in the renal vein; Occlusion - renal vein

Renal vein thrombosis is an uncommon disorder. It may be caused by:

• Abdominal aortic aneurysm
• Hypercoaguable state: clotting disorders
• Dehydration (mostly in infants)
• Estrogen use
• Nephrotic syndrome
• Pregnancy
• Scar formation with pressure on the renal vein
• Trauma (to the back or abdomen)
• Tumor

In adults, the most common cause is nephrotic syndrome. In infants, the most common cause is dehydration.

Symptoms may include:

• Blood clot to the lung
• Bloody urine
• Decreased urine output
• Flank pain or low back pain

An exam may not reveal the specific problem. However, it may indicate nephrotic syndrome or other causes of renal vein thrombosis.

Tests include:

• Abdominal CT scan
• Abdominal MRI
• Abdominal ultrasound
• Duplex Doppler exam of the renal veins
• Urinalysis may show protein in the urine or red blood cells in the urine
• X-ray of the kidney veins (venography)

The treatment is focused on preventing new clot formations and reducing the risk of the clot traveling to other locations in the body (embolization).

You may get medicines that prevent blood clotting (anticoagulants). You may be told to rest in bed or cut down on activity for a short time.

If sudden kidney failure develops, you may need dialysis for a short period.

Renal vein thrombosis most often gets better over time without lasting damage to the kidneys.

Complications may include:

• Acute renal failure (especially if thrombosis occurs in a dehydrated child)
• End stage renal disease
• Blood clot moves to the lungs (pulmonary embolism)
• Formation of new blood clots

Call your health care provider if you have symptoms of renal vein thrombosis.

If you have experienced renal vein thrombosis, call your provider if you have:

• Decrease in urine output
• Breathing problems
• Other new symptoms

In most cases, there is no specific way to prevent renal vein thrombosis. Keeping enough fluids in the body may help reduce risk.

Aspirin is sometimes used to prevent renal vein thrombosis in people who have had a kidney transplant. Blood thinners such as warfarin may be recommended for some people with chronic kidney disease.