Bladder Outlet Obstruction

When the flow of urine is first blocked, the bladder responds by thickening the bladder wall and squeezing harder to push urine out. But if the blockage lasts a long time, the bladder begins to fail and the bladder wall becomes thin.

In some men, the bladder outlet is obstructed by an enlarged prostate caused by prostate cancer or benign prostatic hyperplasia (BPH). Symptoms, which begin slowly and progressively become worse, may include:

• trouble starting the urinary stream
• a weak urinary stream
• frequent urination during the day
• getting up at night to urinate, a condition called nocturia
• urinary urgency, or feeling the need to urinate right away
• urinary incontinence, or leakage of urine

The bladder outlet may also be obstructed by:

• urethral stricture, or narrowing of the urethra
• cancer of the urethra
• meatal stenosis, or narrowing at the point that the urethra reaches the outside of the body

Bladder outlet obstruction is rare in women. But, when its does occur, it is usually caused by neurological disorders or a very large, sagging bladder. Bladder outlet obstruction is very common in older men. It is usually caused by an enlarged prostate from BPH or prostate cancer.

Other causes, which are also more common in men, include:

• bladder stones
• bladder tumors
• physical defects of urethra, which are usually present at birth
• cancer of the urethra

Risks of this condition include urinary tract infection and damage to kidney function. Bladder stones are also a risk of bladder outlet obstruction, as well as a possible cause.

All men, as long as they still have their testicles and are producing testosterone, develop some degree of enlarged prostate as they get older. Prostate cancer is also very common. People who smoke and are exposed to certain chemicals are at increased risk of developing bladder tumors and urethral cancer. Urethral strictures can occur as a result of prior surgery or recurrent episodes of urethritis, an infection of the urethra.

Cessation of smoking is advised to reduce the risk of bladder tumors and urethral cancer.

A person with this condition sometimes has urine left in the bladder after voiding (urinating). When this amount is large, or if the person cannot urinate at all, the healthcare professional can often feel the bulging bladder by touching the lower abdomen. The urine left in the bladder can be measured with an x-ray test known as ultrasound or by placing a tube, called a urinary catheter, in the bladder.

Other tests that help the healthcare professional determine the severity of the condition include:

• uroflowmetry, which measures the rate of urine flow
• pressure flow studies, which compare the pressure in the bladder with the flow of urine during voiding

Bladder outlet obstruction can occasionally lead to a total breakdown of the bladder's ability to empty. If this occurs, the person is not able to void at all. In most cases, bladder outlet obstruction is important only to the extent that it affects the person's quality of life.

However, the cause of this condition can be important. If it is caused by prostate cancer, bladder tumor, or urethral cancer, the cancer must be treated immediately before it spreads to other parts of the body.

There are no risks to others.

A person who has urine left in the bladder after voiding or who cannot urinate at all needs to have the urine drained from his or her bladder. This can be done two ways:

• by placing a urinary catheter through the urethra and into the bladder
• by passing a tube, called a suprapubic cystostomy, through the skin of the lower abdominal wall into the bladder

These drains may be left in for some time. The cause of the bladder outlet obstruction also needs to be treated.

The tube used to drain the urine can cause discomfort and make the person with the condition feel like he or she needs to urinate. A urinary catheter or suprapubic cystostomy that is left in the bladder requires a cumbersome drainage apparatus. It can also cause irritation where it exits from the body.

After treatment, a person should watch for urinary symptoms, such as a weak urinary stream. This might indicate a recurrence of the disease or a failure of the procedure.

Symptoms should be monitored by the person. The underlying cause may warrant regular visits to the healthcare professional.