Medullary sponge kidney
Overview
Medullary sponge kidney is a congenital defect of the kidneys where the kidneys fill with pools of urine.
Symptoms
The symptoms associated with medullary sponge kidney are those related to infection and stone passage. Infection causes fever; back and flank pain; cloudy, frequent, and burning urine; and general discomfort. Stones cause pain in the flank or groin as they pass. They usually cause some bleeding. The bleeding may not be visible in the urine, but it is apparent under a microscope.
Causes
Although some cases of this disorder seem to be inherited, usually the cause is not known.nfection causes fever; back and flank pain; cloudy, frequent, and burning urine; and general discomfort. Stones cause pain in the flank or groin as they pass. They usually cause some bleeding. The bleeding may not be visible in the urine, but it is apparent under a microscope.
Prevention
Diligent monitoring for infection at regular intervals and at the first symptom will give the best long-term results. By drinking extra liquids, most stones can be prevented. The most common kind of stones, calcium stones, can be deterred by regularly taking a medication that encourages urine production (thiazide diuretic).
Diagnosis
Recurring kidney infections, bleeding, or stones will prompt x rays of the kidneys. The appearance of medullary sponge kidney on an intravenous pyelogram (x rays of the upper urinary system) is characteristic.
Prognosis
Ignoring symptoms can result in progressive damage to the kidneys and ultimate kidney failure, but attentive early treatment will preserve kidney function.
Treatment
Many people never have trouble with this disorder. For those that do, infections and stones will need periodic treatment. Infections should be treated with antibiotics early in order to prevent kidney damage. Stones may need to be surgically removed. Often, removal can be accomplished without an incision but rather by reaching up with instruments through the lower urinary tract to grab the stones. There is also a new method of stone treatment called shock wave lithotripsy. A special machine delivers a focused blast of shock waves that breaks stones into sand so that they will pass out naturally. It is considered reasonably safe and usually effective.