Obstructive uropathy occurs when the flow of urine is blocked. The kidneys produce urine in the normal manner but the urine does not drain properly because of the obstruction. Pressure in the urinary tract rises, resulting in hydronephrosis (swelling of the kidneys) and bilateral obstructive uropathy (damage to both kidneys caused by obstruction of urine). Obstructive uropathy may eventually lead to hypertension and/or acute renal failure. Sudden blockage causes acute bilateral obstructive uropathy, while slow, progressive blockage causes chronic bilateral obstructive uropathy.

Acute bilateral obstructive uropathy is usually caused by obstruction of the urethra that occurs suddenly or over a short time. In men, it is most often a result of an enlarged prostate. Other causes in men include prostate cancer, bilateral obstructing kidney stones and bladder cancer. It is much less common in women but can occur as a result of a bladder cystocele, pregnancy and iatrogenic (caused by treatment) injury due to surgery involving the female reproductive organs. Other causes include posterior urethral valves in infant boys, neurogenic bladder, papillary necrosis, coagulated blood, fungus and other rare retroperitoneal processes.

Initially, the bladder reacts to the obstruction through increased irritability. There is a stronger and more frequent urge to urinate, and bladder spasms or incontinence may occur. As urine accumulates, it may lead to stasis of urine and urinary tract infections (see UTI - acute). Urine may back up into the ureters (tubes which carry urine from the kidneys to the bladder) and kidney. Symptoms develop because of urinary retention and/or damage to the bladder, ureters and kidneys.

Acute bilateral obstructive uropathy occurs in about 5 out of 10,000 people.

• Decreased urine output (may be less than 10 mL per day)
• Urinary hesitancy
• Abnormal urine flow -- dribbling at the end of urination
• Incontinence
• Decrease in the force of the urinary stream, stream small and weak
• Urinary frequency/urgency, increased
• Need to urinate at night
• Frequent strong urge to urinate
• Burning or stinging with urination
• Feeling of incomplete emptying of the bladder
• Flank pain or pain in the sides
  • On both sides
  • Began suddenly
• Blood in the urine
• Fever
• Nausea/vomiting
• High blood pressure (hypertension), recent increase
• Urine, abnormal color

• A urinalysis may be abnormal.
• A clean catch urine specimen may show infection within the urinary tract.
• Serum creatinine may increase suddenly, by 2 mg/dL or more over a two-week period.
• Creatinine clearance may be decreased.
• Blood BUN may increase suddenly.
• A blood potassium test may be elevated.
• Arterial blood gas and blood chemistries may show metabolic acidosis.

• IVP
• Renal scan
• Ultrasound of the kidneys
• Abdominal CT scan

• Radionuclide cystogram
• Creatinine - urine

Treatment is focused on relieving the obstruction, which will allow urine to drain from the urinary tract. This allows the body to begin the natural healing process.

Catheterization may provide short-term relief of symptoms. This may be a urethral (Foley) catheter, intermittent self-catheterization, or a suprapubic tube (tube directly draining the bladder through the abdominal wall).

Antibiotics or other medications may need to be given upon diagnosis of infection or renal failure. Initial evaluation and treatment may require hospitalization.

Long-term relief is accomplished through correction of the cause of the obstruction.

Surgical reduction of the prostate, such as by a TURP (transurethral resection of the prostate), corrects an enlarged prostate. Surgical intervention may also be appropriate for other disorders causing blockage of the urethra or bladder neck.

Symptoms usually subside within hours to days if the acute obstruction is immediately relieved. If untreated, the disorder causes progressive damage to the kidneys and may cause kidney failure and death.

• UTI
• Acute renal failure
• High blood pressure
• Reflux nephropathy
• Chronic bilateral obstructive uropathy
• Voiding dysfunction (urinary retention/incontinence)

Call your health care provider if decreased urine output, difficulty urinating, flank pain, or other symptoms of acute bilateral obstructive uropathy occur.

This disorder may not be preventable in many cases. Routine annual physicals with a primary care physician are recommended. If the patient is found to have acute obstructive uropathy, he or she should go to the nearest emergency room and urological consultation is required.