What is Extrinsic Obstruction of the Ureter?

How the Urinary Tract Works?

Male Urinary Tract
Male Urinary Tract
Medical Illustration Copyright © 2015 Nucleus Medical Media, All rights reserved

Female Urinary Tract
Female Urinary Tract
Medical Illustration Copyright © 2015 Nucleus Medical Media, All rights reserved

The bladder and kidneys are part of the urinary system the organs in our bodies that produce, store and pass urine. You have 2 kidneys that produce urine. Then urine is stored in the bladder. The muscles in the lower part of your abdomen hold your bladder in place.

When it isn't full of urine, the bladder is relaxed. When nerve signals in your brain let you know that your bladder is getting full, you feel the need to urinate. If your urinary system is normal, you can delay urination for some time.

Once you are ready to urinate, the brain sends a signal to the bladder. Then the bladder muscles squeeze (or "contract"). This forces the urine out through the urethra, the tube that carries urine from your body. The urethra has muscles called sphincters. They help keep the urethra closed so urine doesn't leak before you're ready to go to the bathroom. These sphincters open up when the bladder contracts.

What is Extrinsic Obstruction of the Ureter?

The ureter is a muscular tube that transfers urine from the kidney to the bladder. It is about 10 inches long, with the upper half in the belly and the lower half in the pelvic area. But what happens when the ureter becomes blocked?

Extrinsic obstruction of the ureter is caused when organs press against the ureter, causing a blockage in the ureter. This affects the flow of urine out of the ureter. After some time, urine can build up, which can hurt the kidney.



What Are the Symptoms of Extrinsic Obstruction of the Ureter?

Often this problem builds slowly and there are no signs. But if the blockage is serious, you will be in pain. In addition to pain, signs may involve:

  • Fever
  • Nausea
  • Throwing up
  • Difficulty voiding
  • Bloody or cloudy urine


What Causes Extrinsic Obstruction of the Ureter?

Some of the risk factors are scar tissue and tumors in nearby areas. Often the causes can vary, but some are:

  • Vascular disease
  • Non-cancerous health issues in women (pregnancy, growths in womb or ovary, Gartner’s duct cyst, endometriosis, uterine prolapse, intraoperative ureteral injury)
  • Health problems of the GI tract (Crohn’s disease, swelling of the appendix, diverticulitis, pancreatic lesions)
  • Other abdominal issues


How Is Extrinsic Obstruction of the Ureter Diagnosed?

Symptoms of this problem are common, and can make it hard to diagnose. Imaging studies are the key to diagnosing the condition, you may receive an:

These studies will often show where the blockage is, and may be able to pinpoint the cause. Urine and blood tests can also be used to find out how well the kidneys are working.



How Is Extrinsic Obstruction of the Ureter Treated?

Nephrostomy tube and Drainage pouch
Nephrostomy tube and Drainage pouch
National Institute of Diabetes and Digestive and Kidney Diseases,
National Institutes of Health

Treatment often depends on the nature of the blockage. First efforts involve draining urine from the kidney(s). This can be done with:

  • A ureteral stent: a thin, hollow plastic tube is placed between the kidney and bladder, holding the ureter open to allow urine to drain.
  • Nephrostomy: a catheter is placed (guided by X-ray or ultrasound) through the skin into the kidney to drain urine.
  • After relief of the blockage, laparoscopic or open surgery may be performed to permanently relieve the blockage.


What Can Be Expected After Treatment?

The results can vary. Any kidney damage caused by the blockage can be lasting. But if the cause is found and treated early, the harm may be brief. If only 1 kidney is affected, the other kidney often keeps working well enough so that kidney failure does not happen.