MS vein treatment cleared for trials
TORONTO – A long-awaited national trial of a controversial experimental treatment for multiple sclerosis has been given the go-ahead and will soon begin recruiting patients, federal Health Minister Leona Aglukkaq announced Friday.
Aglukkaq, in Halifax for a meeting with provincial and territorial health ministers, said about 100 MS patients will be enrolled in the Phase I and II trial to assess the safety of the procedure to unblock narrowed neck veins and its efficacy in improving MS symptoms.
The condition — dubbed chronic cerebrospinal venous insufficiency, or CCSVI — has been proposed as a possible cause of MS by Italian vascular surgeon Paolo Zamboni.
More than three years ago, Zamboni hypothesized that narrowed and twisted veins in the neck and chest create a backup of blood in the brain, resulting in iron deposits that could cause the brain lesions typical of MS.
The disease causes the destruction of myelin, the protective sheath around nerves throughout the body, leading to progressive physical and cognitive disability. An estimated 55,000 to 75,000 Canadians have MS, and the country has one of the highest rates of the incurable disease in the world.
“We’ve always said that we needed the science behind the actual procedure,” Aglukkaq told reporters. “This area of MS clinical trials is very important to many of our constituents and today is huge progress.”
Dr. Anthony Traboulsee, medical director of UBC Hospital’s MS Clinic, will lead the $6-million study, which will be conducted initially in Vancouver and Montreal. Medical and ethical approval is also being sought for parts of the trial to be conducted in Quebec City and Winnipeg.
“It’s going to be a randomized-control study where patients who have the presence of CCSVI will be randomly selected to either have the venoplasty, which is dilation of the vein, or a sham treatment, which is not an actual dilation, just a pretend dilation,” Traboulsee said from Vancouver.
“And after a year, the groups will switch so that everybody eventually gets the dilation of the vein.”
A venoplasty to widen veins is the same technique as an angioplasty used to expand coronary arteries; a tiny balloon is fed into the blood vessel, then expanded. None of the participants will know which treatment they received or during which half of the study, Traboulsee said.
“The patients won’t know when they’re getting the dilation, the first time or the second time, so it doesn’t bias their interpretation of benefit,” he said.
Thousands of Canadians with MS have reportedly travelled to clinics outside the country, paying thousands of dollars for the vein-widening procedure since Zamboni’s theory first made headlines in late 2009.
Many patients — but by no means all — reported their symptoms had improved following CCSVI treatment, fuelling insistent calls by many MS patients and their advocates to allow doctors to perform the procedure in Canada.
But with several deaths and complications attributed to the surgery — and studies on CCSVI around the world showing mixed results at best — an expert medical panel advised Ottawa to first mount a clinical trial to test Zamboni’s theory.
“We’ve been surveying patients who have gone out of the country for the treatment and we found a complication rate of 11 to 12 per cent. That’s what patients are reporting,” he said. “My impression is it’s mostly related to stents, and we’re not going to be using stents in our study. We don’t think the stents are the best idea at this point.”
Stents are small mesh cylinders inserted into blood vessels to keep them propped open. Their use in veins is controversial, as the stents can cause blood clots or migrate from their original site. Even Zamboni does not advocate their use in his CCSVI treatment.
“There has been a lot of controversy around it,” Traboulsee said of the procedure. “That’s why I think it’s important to move this forward and get some final answers to it.”
“Because so many Canadians are going out of the country to have this procedure done, if we don’t bring some resolution to it soon, we won’t be able to give people the information they need to make safe, informed decisions.”