Retroperitoneal Fibrosis: Causes, Symptoms, Treatment, Complications, Diagnosis

Retroperitoneal fibrosis is a condition in which excess fibrous tissue develops in the retroperitoneal area in the body, which is a space behind the stomach and intestine.

Fibrosis is the growth of excess connective tissue that leads to the formation of mass. This compresses and blocks the ureters, the tubes that carry urine from the kidney to the bladder.

The tissue mass can block either one or both the ureters. As the urine backs up in the ureters, the harmful material enters the blood and damages the kidney. It can lead to kidney failure if not addressed early.

Retroperitoneal fibrosis starts with the inflammation and fibrosis of the abdominal aorta, a large artery that brings blood from the heart to the areas below the kidney. As the disease progresses the arteries carrying blood to the legs and kidney get affected. This leads to pain, leg swelling, and a reduction in kidney function.

The cause of retroperitoneal fibrosis remains unknown in two-third of cases.⁽¹⁾

Age and gender are the main risk factors as it is known to occur more between the ages of 40 and 60 and occurs twice as often in men as in women.⁽²⁾

The conditions linked with retroperitoneal fibrosis include:

• Smoking
• Tuberculosis
• Exposure to asbestos
• Actinomycosis, a bacterial infection
• Histoplasmosis, a fungal infection
• Pelvic and abdominal tumors

Retroperitoneal fibrosis can also be associated with:

• A recent pelvic and abdominal surgery
• Cancer treatment involving brain
• Migraine and blood pressure medication

In retroperitoneal fibrosis, there is a decrease in the blood flow from the aorta to the lower part of the body.

In the early stages of Retroperitoneal fibrosis when the body reacts to reduced blood flow, symptoms are:

• Dull pain in abdomen and back
• Leg pain
• Discoloration on one or both legs
• Pain between upper abdomen and back
• Intense abdominal pain with bleeding and hemorrhage
• Swelling of one leg

As the disease progresses the symptoms of Retroperitoneal fibrosis include:

• Severe abdominal pain
• Back pain
• Fever
• Difficulty in urination
• Loss of appetite
• Nausea and Vomiting
• Kidney failure
• Low levels of red blood cells
• Difficulty in thinking clearly
• Impaired limb movement

It is important to see the doctor immediately as the urine output decreases along with abdominal and lower back pain.

The complications related to Retroperitoneal fibrosis vary according to the size and location of the excess growth. It can accordingly cause damage to the areas served by the abdominal aorta.

The swelling and blockage of the ureter if not treated can lead to serious problems such as chronic kidney failure, long-term blockage of ureters. This can further lead to urine back-up and kidney swelling.

Untreated retroperitoneal fibrosis can lead to cutting off the blood supply to the legs that have dangerous complications.

CT scan and MRI scan are needed for an accurate diagnosis of Retroperitoneal fibrosis.

Additional tests include:

• Blood test to measure kidney function, anemia, and inflammation
• Ultrasound of kidneys
• Biopsy for cancer cells
• X-ray of kidney and ureters, also known as intravenous pyelogram

Treatment for Retroperitoneal fibrosis depends on the severity and location of the fibrosis. In the early stages anti-inflammatory medications, corticosteroids, and immunosuppressants are prescribed.

After the fibrosis has blocked one or both of the ureters, the doctor needs to clear the obstruction. For this, the urine has to be drained with the help of a stent or drainage tube that is inserted through the back into the kidney.

In some cases of Retroperitoneal fibrosis surgery would be needed to:

• Free the affected ureter from fibrosis
• Wrap the affected ureter in fat tissue to protect it from fibrosis regrowth
• Reposition the affected ureter away from inflammation as it helps prevent the blockage from happening again
• The treatments aim to remove the blockage, repair the affected ureter, and prevent it from happening again.

If diagnosed and treated at early stages the long-term outlook of Retroperitoneal fibrosis is very good. In the cases where kidney damage is minimal and surgery is successful, there are 90 percent chances of long-term success.⁽³⁾

In severely affected cases, damage can be permanent and there can be a need for a kidney transplant.