Retroperitoneal fibrosis is a rare condition in which the ureters (tubes that carry urine from the kidneys to the bladder) are obstructed by a mass located behind the stomach and intestines. Estimated to affect one out of 100,000 people, this blockage prevents normal urination and can create serious issues for the kidneys if they become damaged due to urine buildup.
In the early stages, the person--usually middle-aged men--may feel a dull pain in the abdomen that advances, but eventually urinary output may be greatly minimized or nonexistent.
Causes of Retroperitoneal Fibrosis
Just why these fibrous masses form is unknown. In 60 to 70 percent of cases, the condition appears suddenly and for no known reason. However, it may be linked to a number of other conditions and events, such as:
- Inflammation due to infections
- Scar tissue from surgery
- Autoimmue conditions (thyroid disease)
- Radiation therapy
- Inflammatory bowel disease
- Medications used for migraine headaches (such as beta-blockers, methysergide and ergotamines), high blood pressure (hydralazine), and Parkinson's disease (particularly when pergolide is taken with levodopa) have vasoactive substances that constrict or dilate the blood vessels. Prolonged constriction and dilation can lead to perivascular edema, cause plasma content to leak from the blood vessels through pores or tears in the cell membranes, and spark the fibroblastic response.
- Retroperitoneal trauma (the space in the abdominal cavity behind the membrane that makes the lining of the cavity)
Symptoms of Retroperitoneal Fibrosis
The early symptoms of retroperitoneal fibrosis include:
- Diminished blood flow affecting the legs; the legs change color and ache
- Frequent urination
- Swelling of one leg
- Phlebitis, or the swelling of a superficial vein, usually in the leg
- Dull pain in the stomach that intensifies over time
The later symptoms are more severe. They include:
- Anuria, or no urine output
- Ascites, defined as the buildup of fluid in the space between the stomach’s organs and the stomach’s lining. This space is called the peritoneal cavity.
- Blockage of either the small or large bowel
- Compression of the spinal cord
- Intestinal tissue death, causing severe stomach pain with extensive bleeding
- Jaundice (yellow pigmentation of the skin)
- Nausea and vomiting
- Reduced urine output
- Cognitive disruption due to kidney failure and toxic chemical build-up in the blood
Patients diagnosed with retroperitoneal fibrosis usually have some level of renal insufficiency. Also, half of those with retroperitoneal fibrosis have hypertension or high blood pressure.
Diagnosis of Retroperitoneal Fibrosis
When diagnosing retroperitoneal fibrosis, a physical examination is often the first course of action, followed by an abdominal CT scan, which uses X-rays to create images of the belly.
Other tests include:
- Blood urea nitrogen (BUN) test: gauges how much nitrogen is in the blood to determine how well the kidneys are functioning.
- Biopsy: a piece of tissue is taken from the mass so that it can be inspected under a microscope
- Creatine test: Creatine is a waste product filtered by the kidneys and eliminated through the urine. If the kidneys aren’t working well, creatinine builds up in the blood. Creatinine levels are measured in the blood and urine, again assessing kidney health.
- Intravenous pyelogram (IVP): Contrast dye is injected into the patient's arm and X-rays are taken of the bladder, kidneys, and ureters (tubes that funnel urine from the kidneys to the bladder) to see how the dye collects in the urine and how well it is removed by the kidneys.
- CT scan: takes and combines a number of X-rays that have been taken from different angles and uses a computer process to produce cross-section images of the soft tissues and bones.
- Ultrasound uses high-frequency sound waves to produce images of the kidneys and other organs
Treatment of Retroperitoneal Fibrosis
When treating retroperitoneal fibrosis, patients with this problem generally are given anti-inflammatory medications first. If they do not work, medications that subdue the immune system are tried. In the event these fail, more invasive methods, namely stents and surgery, are used.
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