Obstructive uropathy

Obstructive uropathy occurs when urine cannot drain through a ureter (a tube that carries urine from the kidneys to the bladder). Urine backs up into the kidney and causes it to become swollen (hydronephrosis).

Obstructive uropathy can affect one or both kidneys. It can occur suddenly, or be a long-term problem.

Common causes of obstructive uropathy include:

• Bladder stones
• Kidney stones
• Benign prostatic hyperplasia (enlarged prostate)
• Bladder or ureteral cancer
• Colon cancer
• Cervical cancer
• Uterine cancer
• Any cancer that spreads
• Scar tissue that occurs inside or outside of the ureters
• Problems with the nerves that supply the bladder

Rarely, the problem occurs during pregnancy. This condition is called idiopathic hydronephrosis of pregnancy.

Symptoms depend on whether the problem starts slowly or suddenly, and if one or both kidneys are involved. Symptoms may include:

• Mild to severe pain in the side of the body and the back (flank pain). The pain may be felt on one or both sides.
• Fever
• Nausea or vomiting
• Weight gain or swelling (edema)

You may also have problems passing urine, such as:

• Urge to urinate often
• Decrease in the force of urine stream
• Dribbling of urine
• Not feeling as if the bladder is emptied
• Need to urinate more often at night
• Decreased amount of urine
• Blood in urine

Imaging studies are done to diagnose obstructive uropathy. Commonly used tests include:

• Ultrasound of the belly area (abdomen) or pelvis
• CT scan of the belly area (abdomen) or pelvis
• Intravenous pyelogram (IVP)
• Voiding cystourethrogram
• Renal nuclear scan
• MRI

Stents or drains placed in the ureter or in a part of the kidney called the renal pelvis may provide short-term relief of symptoms.

Nephrostomy tubes, which drain urine from the kidneys through the back, may be used to bypass the blockage.

A Foley catheter, placed through the urethra into the bladder, may also be help urine flow.

Short-term relief from the blockage is possible without surgery. However, the cause of the blockage must be removed and the urinary system repaired. Surgery may be needed for long-term relief from the problem.

The kidney may need to be removed if the blockage causes severe loss of function.

If the blockage comes on suddenly, kidney damage is less likely if the problem is detected and repaired right away. Often, the damage to the kidneys goes away. Long-term damage to the kidneys may occur if the blockage has been present for a long time.

If only one kidney is damaged, chronic kidney problems are less likely.

You may need dialysis or a kidney transplant if there is damage to both kidneys and they do not function, even after the blockage is repaired.

Obstructive uropathy can cause permanent and severe damage to the kidneys, resulting in kidney failure.

If the problem was caused by a blockage in the bladder, the bladder may have long-term damage. This may lead to problems emptying the bladder or leakage of urine.

Obstructive uropathy is associated with a higher likelihood of urinary tract infections.

Call your health care provider if you have symptoms of obstructive uropathy or suspect you may have this condition.

Obstructive uropathy can be prevented by treating disorders that can cause it.

Meldrum KK. Pathophysiology of urinary tract obstruction. In: Wein AJ, Kavoussi LR, Partin AW, Peters CA, eds. Campbell-Walsh Urology. 11th ed. Philadelphia, PA: Elsevier; 2016:chap 48.

Zeidel ML. Obstructive uropathy. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 123.