FDA: Controversial stenting treatment for MS may endanger patients
Some researchers believe that CCSVI, which is characterized by stenosis of veins in the neck and chest, may cause multiple sclerosis (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.
“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,” William Maisel, MD, MPH, chief scientist and deputy director for science in the FDA’s Center for Devices and Radiological Health, said in a statement.
“The Society of Interventional Radiology (SIR) agrees with the FDA that well designed, rigorously conducted, properly targeted clinical trials need to be performed to better evaluate the role of CCSVI in the care of MS patients,” Marshall E. Hicks, MD, head, division of diagnostic imaging at MD Anderson Cancer Center and president of SIR, wrote in an email to Health Imaging.
SIR issued a position statement in 2011 supporting high-quality clinical research to determine the safety and effectiveness of interventional MS treatments. Meanwhile patient advocacy has fueled demand for the procedure among patients with MS, with physicians providing the treatment for patients who prefer not to wait until definitive trials are completed.
“The studies that have been reported to date, including the studies reported at the SIR meeting, have been single center retrospective series which have highlighted the potential for this treatment to improve the quality of life in patients with MS. These are the types of studies which must first be performed and reported on in order to build an initial understanding of the procedure and the entity being treated. These initial studies are also able to highlight the potential safety issues that may be encountered with these procedures. Most of the studies published or presented to date have seen little risk for significant complications in association with this procedure. However, scattered significant complications have been reported and we agree that patients should be made aware of these risks when considering this procedure,” Hicks noted.
The experimental procedure uses balloon angioplasty devices or stents to widen narrowed veins in the chest and neck. However, the FDA has learned of death, stroke, detachment and migration of the stents, 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.
The FDA also notified physicians and clinical investigators who are planning or conducting clinical trials using medical devices to treat CCSVI that they must comply with FDA regulations for investigational devices. Any procedures conducted are considered significant risk clinical studies and require an investigational device exemption.
SIR recommends following the FDA alert and close communications between physician and patient, Hicks wrote.