Retroperitoneal fibrosis is a rare condition caused by overgrowth of tissue behind the stomach and intestines. This condition develops if tissue overgrowth blocks the ureters, the tubes that transport urine from the kidneys to the bladder. Retroperitoneal fibrosis is associated with cancer in approximately eight percent of cases, but up to 70 percent of cases are idiopathic and have no known cause.
There is no conclusive evidence pointing to a definitive cause of retroperitoneal fibrosis, but it often is associated with the presence of autoimmune disease. One theory is that the autoimmune disease occurs because the immune system attacks proteins contained within atherosclerosis plaques. According to this theory, advanced plaques leak proteins into surrounding tissue and stimulate an immune reaction that causes inflammation and eventual build-up of fibrous scar tissue.
In the early stages, retroperitoneal fibrosis symptoms include dull pain in the back, lower abdomen or side; leg pain; decreased blood flow causing change in color of the legs; and leg swelling, typically in one leg. If the condition does not receive immediate treatment, urine output gradually decreases as the kidneys fail. In the event of kidney failure, symptoms include nausea, vomiting and confused thinking. If intestinal tissue begins to die, hemorrhaging and severe abdominal pain can result. Possible complications of the condition include venous inflammation, which can lead to deep vein thrombosis; jaundice; testicular swelling; bowel obstruction; and compression of the spinal cord.
Kidney damage can be permanent if not treated promptly. This is a particular problem because of the difficulty in diagnosing this condition early enough to prevent damage. The early symptoms are nonspecific, resulting in a relatively long diagnostic process and a risk of permanent kidney disease.
The most effective retroperitoneal fibrosis treatment is a combination of surgery and other types of therapy, such as medication and symptom management. The most important aspects of treatment are preserving as much kidney function as possible and ensuring that other organs do not become affected. Even so, there are no generally accepted treatment regimens for this condition.
In terms of medication, corticosteroids are used to reduce inflammation in the early stages of disease. Tamoxifen, an anti-estrogen drug, also has shown positive effects in reducing symptoms. Both drugs have risks for long-term use, however, and therefore are used on a case-by-case basis rather than being part of a standard treatment protocol. Immunotherapeutic drugs with greater specificity and fewer long-term side effects than steroids have been in the experimental stages.
The most effective surgical treatment involves laparoscopic surgery to remove and reconstruct fibrous tissue masses. This type of surgery is preferred over open surgery, because the latter is much more invasive and risky, with a mortality rate of almost 10 percent. Another possible surgical procedure involves temporarily or permanently fitting the ureters with shunts to keep them open and prevent urine blockage.
