Obstructive uropathy involves a blockage of the flow of urine, causing it to back up and injure one or both kidneys.
Causes, incidence, and risk factors
Obstructive uropathy occurs when urine cannot drain through a ureter because of an obstruction, often ureteral or kidney stones. Urine backs up into the kidney and causes distention of the renal pelvis and calyces (hydronephrosis).
Obstructive uropathy is further differentiated by whether it affects one or both kidneys (unilateral or bilateral) and whether it occurrs suddenly (acute) or is long-standing (chronic):
- Chronic unilateral obstructive uropathy
- Chronic bilateral obstructive uropathy
- Acute unilateral obstructive uropathy
- Acute bilateral obstructive uropathy
Common causes of obstructive uropathy include the following:
- Urinary tract stones o Ureteral stones o Bladder stones
- Urinary tract tumors
- Retroperitoneal fibrosis
- Benign prostatic hyperplasia
- Adjacent organ tumors
- Colon cancer
- Cervical cancer
- uterine cancer
- Any cancer that metastasizes (spreads)
- Idiopathic hydronephrosis of pregnancy
Symptoms associated with obstructive uropathy vary depending on whether the obstruction is acute or chronic, whether it is unilateral or bilateral, whether it is complete or partial, and what caused it. Common symptoms of obstructive uropathy include the following:
- Flank pain o Bilateral or unilateral o Colicky or severe
- Urinary tract infection
- Difficulty or pain while urinating
- nausea or vomiting
- Renal failure
- Weight gain or swelling (edema)
- Decreased urine output
- Blood in the urine
Signs and tests
The diagnosis of obstructive uropathy is made on imaging studies. Common radiographic studies used to diagnose obstructive uropathy include:
- Abdominal ultrasound
- Abdominal CT scan
- Intravenous pyelogram (IVP)
- Voiding cystourethrogram
- Renal nuclear scan
Stents or drains placed in the ureter or in 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 obstruction. A Foley catheter, inserted through the urethra, may also be helpful.
Although temporary relief from the obstruction can be achieved without surgery, the cause of the obstruction must be removed and the urinary system repaired. Long-term relief from obstructive uropathy requires surgery.
If acute obstruction is rapidly diagnosed and repaired, renal damage is minimal or reversible - regardless of being unilateral or bilateral. If chronic unilateral obstruction is not relieved promptly there could be permanent damage to the kidney. Chronic unilateral obstruction usually does not cause renal insufficiency or failure because most patients have normal function from the other kidney.
Chronic bilateral obstruction may lead to renal insufficiency or failure because both kidneys may become damaged and fail to function even after obstruction is repaired.
Obstructive uropathy can cause permanent and severe damage to the kidneys, resulting in renal failure. Obstructive uropathy caused by bladder outlet obstruction can lead to permanent and severe damage to the bladder, resulting in problems such as incontinence, urinary retention.
Calling your health care provider
Contact your health care provider if you have symptoms of obstructive uropathy or believe that you may be suffering from this condition.
Obstructive uropathy can be prevented by preventing the disorders that cause it.
by Simon D. Mitin, M.D.
All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.