Surgical Shunts Implanted In Patients May Have Caused Mesothelioma: Study

New research suggests that chronic inflammation from medically-implanted shunts could result in the development of mesothelioma; a deadly form of lung disease that is associated with asbestos exposure and rare cases of radiation.

In a study presented at the annual meeting of the College of American Pathologists, researchers from the Mayo Clinic warn that long-term in-dwelling shunts, used in the brain and other parts of the body to relieve fluid pressure, may potentially be a cause of mesothelioma.

Generally, the only two potential causes of mesothelioma have been believed to be the result of breathing asbestos fibers, and radiation exposure in some cases. As a result of a long latency period of between 20 and 40 years between exposure to asbestos and diagnosis, the cancer is often at a very advanced stage by the time it is discovered and usually results in death.

The shunts, however, do not contain asbestos and are not associated with radiation exposure, according to the researchers.

The Mayo Clinic researchers looked at data on seven patients at the Mayo Clinic, all of whom had long-term in-dwelling shunts, and all of whom had the exact same rare form of peritoneal mesothelioma.

The patients underwent imaging and biopsies, and six of the seven were found to have no asbestos or radiation exposure. The patients had the shunts for a mean duration of 21 years.

Following their diagnoses, the mean survival was only 8.7 months, as many had reached advanced stages of the disease by the time they were diagnosed.

Researchers theorized that the mesothelioma developed due to chronic irritation, which has been linked to other forms of cancer. They also noted, despite the surety of most linking asbestos exposure to mesothelioma, only 50% to 70% of mesothelioma patients can definitively say they were exposed to asbestos.

“Mesothelioma is a previously unrecognized complication of shunt catheters in the thorax and abdomen,” the researchers concluded. “The mechanism is unknown, but chronic irritation of the pleura or peritoneum may play a role. Although rare, mesothelioma should be considered in patients with a shunt who present with new ascites or effusions.”

The study has not yet been peer reviewed or published in a medical journal.