The U.S. Food and Drug Administration (FDA) is alerting people with MS to the risks of serious injuries and death associated with certain procedures to treat chronic cerebrospinal venous insufficiency (CCSVI). The benefits of these experimental procedures, commonly known as “liberation therapy” or the “liberation procedure” have not been proven, says the FDA, and their promotion as a treatment for MS may lead people with the disease to make treatment decisions without being aware of the serious risks involved.
The FDA’s announcement is also intended to notify physicians and clinical investigators planning or conducting clinical trials using medical devices to treat CCSVI that they must comply with FDA regulations for investigational devices.
The “liberation procedure” uses balloon angioplasty devices or stents to widen narrowed veins in the chest and neck. However, the FDA has learned of cases involving death, stroke, detachment, and migration of the stents, as well as damage to the treated vein, blood clots, cranial nerve damage and abdominal bleeding associated with the experimental procedure. Balloon angioplasty devices and stents have not been approved by the FDA for use in treating CCSVI.
Some researchers believe that CCSVI, which is characterized by a narrowing (stenosis) of veins in the neck and chest, may cause MS or may contribute to the progression of the disease by impairing blood drainage from the brain and upper spinal cord. However, studies exploring a link between MS and CCSVI are inconclusive, and the criteria used to diagnose CCSVI have not been adequately established, according to the FDA.
The FDA gave the following reasons for issuing the warning:
There is no clear diagnostic evidence that CCSVI exists as a distinct clinical disorder or is linked to MS.
Venous stenoses seen on imaging tests may be normal variants that do not cause any symptoms or disease, since they are sometimes seen in healthy people.
The safety and effectiveness of using balloon angioplasty devices or stents in the internal jugular or azygos veins have not been established for any clinical condition; nor has the FDA approved the use of these devices in these veins.
There is no clear scientific evidence that the treatment of internal jugular or azygos venous stenosis is safe in MS patients, impacts the symptoms of MS, changes the overall course of MS, or improves the quality of life for MS patients.
It is possible that stent placement can worsen any venous narrowing. This is because further narrowing has been shown to sometimes occur within stents placed in veins, due to the body’s response to the implant.
“Because there is no reliable evidence from controlled clinical trials that this procedure is effective in treating MS, FDA encourages rigorously-conducted, properly-targeted research to evaluate the relationship between CCSVI and MS,” said William Maisel, M.D., M.P.H., chief scientist and deputy director for science in the FDA’s Center for Devices and Radiological Health. “Patients are encouraged to discuss the potential risks and benefits of this procedure with a neurologist or other physician who is familiar with MS and CCSVI, including the CCSVI procedures and their outcomes.”
Complications following CCSVI treatment can be reported through MedWatch, the FDA Safety Information and Adverse Event Reporting program. For more information visit www.fda.gov/Safety/MedWatch/HowToReport.
In February 2012, the FDA sent a warning letter to a sponsor/investigator who was conducting a clinical study of CCSVI treatment without the necessary approval. The sponsor/investigator voluntarily closed the study.
The FDA says it will continue to monitor reports of adverse events associated with “liberation therapy” or the “liberation procedure” and keep the public informed as new safety information becomes available.