Urinary Obstructions

Normally, urine is formed in the kidneys, flows through the ureters to the bladder, and is released through the urethra. A urinary obstruction blocks the normal flow of urine, causing it to back up toward the kidneys. Urine flowing the wrong way in the urinary tract can cause infections and kidney damage. Urinary obstructions affect about one in every 1,000 people, and they vary widely by the cause and type of blockage.

The obstruction can involve one or both kidneys, called unilateral or bilateral obstruction. The blockage may be complete or partial, and it can occur suddenly or develop over time. An obstruction can occur in any part of the urinary tract, whether upper (kidneys and ureters) or lower (bladder and urethra). Where an obstruction is located will determine the best treatment option.


Diagnosis

The physician may order the following tests, which could reveal a urinary obstruction:

• Urinalysis
• Blood and urine tests to assess kidney function
• Abdominal X-rays

These tests check for urinary tract infection, which can result from an obstruction:

• Urine culture
• CBC test to identify increased white blood cell count

Cystoscopy
A small, flexible tube which includes an optical system is inserted into the body through the urethra. The optical system allows physicians to see inside the body.

Renal ultrasound
Sound waves are used to produce an internal view of the kidneys, ureters, bladder and urethra.

Voiding cystourethrogram
A catheter, or tube, is inserted through the urethra to fill the bladder with a liquid contrast material. Then the bladder and urethra are X-rayed before and during urination.

Intravenous pyelogram (IVP) or excretory urogram
A contrast material is injected into a vein in the arm. X-rays are taken as the contrast moves through the kidneys, ureters and bladder.

CT scan
This test uses a series of thin X-ray slices to produce two-dimensional images of the urinary system.

CT urogram
This test combines IVP with CT of the abdomen and pelvis.

Renal nuclear scan
Similar to an IVP, except a small amount of radioactive solution is injected and viewed through a special camera. This test can evaluate the kidneys, how they are functioning and if they have been injured by a urinary obstruction.

Abdominal MRI
Powerful magnets and radio waves produce detailed images of the urinary system.


Treatment

Temporary, or Short-term, Treatment

A urinary obstruction can cause acute pain or potentially serious problems if the urine is backing up into the kidneys. In these cases, the patient may need immediate relief. Depending on the location of the obstruction, these short-term treatments can include:

• A catheter (small tube) inserted through the urethra into the bladder to drain urine from the bladder.
• A stent (hollow tube) in the ureter (between the kidney and bladder) to keep the ureter open.
• A nephrostomy tube can inserted through the patient's lower back to drain urine directly from the kidney (percutaneous nephrostomy).

Cystoscopy
A cystoscope is a small, flexible tube which includes an optical system. The cystoscope is inserted into the body through the urethra. The optical system allows doctors to see inside the body and perform surgery by inserting and manipulating equipment through the tube. For patients with urinary obstruction, cystoscopy is used to diagnose urinary tract disorders, such as enlarged prostate. During the procedure, the doctor can also surgically remove obstructions such as kidney stones.


Permanent, or Long-term, Treatments

Treatment options depend on the kind of urinary obstruction and may involve medication or surgery. The benefits to patients are more rapid recovery and minimal scarring. Should the obstruction affect kiddney function, kidney specialists (nephrologists) can advise on treatment options.

If both kidneys are permanently damaged and no longer function as a result of the urinary obstruction,

Treatment of Infections
Once urine has backed up into the urinary system, it can cause an infection that is difficult to cure. Mayo Clinic urologists coordinate with the patient's primary care or local physician to closely monitor the patient for urinary tract infections and to provide treatment.