The Canadian Agency for Drugs & Technologies in Health
Issue 20 - April 2011
"An Update on the Investigation of Chronic
Cerebrospinal Venous Insufficiency for the
Treatment of Multiple Sclerosis" - Environmental Scan
http://www.cadth.ca/media/pdf/MS_Libera ... s-20_e.pdf
Page 1 of 14
Context Multiple sclerosis (MS) is a chronic progressive neurological disease common in young adults.1 Canada has one of the highest prevalence rates of MS in the world.2 MS causes significant disability due to mobility and vision problems, fatigue, incontinence, and cognitive impairment.1 The Public Health Agency of Canada estimated that the total costs associated with MS in 2000-2001 for hospitalization, treatment, and lost productivity due to morbidity and premature mortality were $950.5 million.1 Treatments involve suppressing or modifying the immune response, but there is currently no cure for MS.3 Although MS is commonly believed to be an autoimmune disease, the evidence to support this concept has been questioned.4 An alternative hypothesis has been put forth by Dr. Paolo Zamboni, a former vascular surgeon and professor at the University of Ferrara in northern Italy. Dr. Zamboni believes a phenomenon termed chronic cerebrospinal venous insufficiency (CCSVI), an abnormality in blood drainage from the brain and spinal cord due to the narrowing of veins, may cause the buildup of iron deposits and contribute to inflammation and nervous system damage.5 Initial findings that CCSVI may be associated with MS were published in 2009 from a study of 65 patients with MS.6 Results from a second study suggested that treating CCSVI with endovascular angioplasty (the insertion of a tiny balloon or stent into blocked veins to improve blood flow), also referred to as the liberation procedure, is feasible and safe.7 Results from other studies have not supported the hypothesis that CCSVI is present in patients with MS.8-12 Findings from a clinical trial published in April 2011, involving 499 participants, indicate that CCSVI may be a consequence rather than a cause of MS.13 The results showed that only 56.1% of MS patients had CCSVI. Furthermore, 42.3% of participants had other neurological diseases and 22.7% of healthy controls also had CCSVI. It was also noted that CCSVI prevalence was significantly higher in patients with advanced progressive MS than those with non-progressive MS.
The CCSVI surgery for MS patients has not been approved by Health Canada and is not covered by provincial health insurance plans. In 2010, an estimated 3,000 Canadians travelled to clinics in the United States, Bulgaria, Poland, India, Costa Rica, and Mexico, each paying thousands of dollars for the procedure.14 Among them was an Ontario man who died in October 2010 from complications of the procedure, which he received in Costa Rica.15 Based on the risks associated with the CCSVI surgery and the inconclusive results of preliminary research, there have been recommendations that rigorous large-scale clinical trials are required to determine whether CCSVI is a clinically important factor in the development or progression of MS.16,17 In light of the high prevalence of MS in Canada, the CCSVI procedure has sparked unprecedented interest and generated considerable debate in the medical and scientific communities. Politicians have faced increasing pressure from the public to provide funding for clinical trials.
The purpose of this report is to review recent developments in the investigation of CCSVI for the treatment of MS. This report will update information presented in a previous Environmental Scan, released in December 2010.18 The following questions will be addressed:
Which clinical trials in North America are currently studying the association of CCSVI with MS?
What is the status of funding for CCSVI research in Canada?
What other initiatives are taking place in Canada with regard to CCSVI?