Renal (kidney) cortical necrosis is death of the tissue in the outer part of kidney (cortex) that results from blockage of the small arteries that supply blood to the cortex and that causes acute kidney failure.

• Usually the cause is a major, catastrophic disorder that decreases blood pressure.
• Symptoms may include dark urine, decreased urine volume, fever, and pain in the side of the body.
• Sometimes an imaging test or tissue analysis (biopsy) is done to confirm the diagnosis.

Renal cortical necrosis can occur at any age. About 10% of the cases occur in infants and children. More than half of the newborns with this condition had deliveries complicated by premature detachment of the placenta. The next most common cause is a bacterial infection of the bloodstream (sepsis). In children, renal cortical necrosis may occur after severe infection, severe dehydration, shock, or the hemolytic-uremic syndrome (see Platelet Disorders: Thrombocytopenia (ITP, TTP)).

In adults, sepsis causes one third of all cases of renal cortical necrosis. Other causes in adults include rejection of a transplanted kidney, burns, inflammation of the pancreas, injury, snakebite, use of certain drugs, and poisoning caused by certain chemicals.

About half of the cases in women occur after complications of pregnancy, such as premature detachment of or abnormal position of the placenta, bleeding from the uterus, infections immediately after childbirth, blockage of arteries by amniotic fluid, death of the fetus within the uterus, and preeclampsia.

Symptoms

The urine often becomes red or dark brown because of the presence of blood. Pain along both sides of the lower back may occur. A fever is often present. Changes in blood pressure, including mildly high pressure or even low pressure, are common. Urine flow may slow or stop.

Diagnosis

Doctors may have difficulty making a diagnosis of renal cortical necrosis because it may resemble other types of acute kidney failure. Doctors may suspect renal cortical necrosis based on symptoms in people who have predisposing conditions. The diagnosis is often confirmed with an imaging test such as computed tomography (CT) angiography. Kidney biopsy can give doctors the most accurate diagnostic information, but a biopsy involves removing kidney tissue and may be unnecessary if the diagnosis is evident. Thus, a biopsy is not done in most people.

Blood tests may reveal abnormally shaped red blood cells circulating in the blood. The small amount of urine that is produced contains protein and many white and red blood cells, along with kidney cells and other debris.

Prognosis and Treatment

In recent years, with improved treatment, prognosis has improved. About 80% of people live a year or longer, although most people need permanent dialysis or kidney transplantation.

Treatment is supportive care, which may involve giving intravenous fluids, blood transfusion, antibiotics, dialysis, or a combination.

Last full review/revision December 2007 by Seyed-Ali Sadjadi, MD