A controversial treatment known as "liberation therapy" is ineffective in patients with multiple sclerosis, according to Canadian findings from one of the most rigorous studies of the procedure to date.
The procedure, which opens up veins in the neck that drain blood from the brain and spinal cord, is unapproved in Canada. But surgeons in the United States, Latin America and Eastern Europe continue to offer the treatment, despite a lack of evidence to support its use.
In the study, researchers from the University of British Columbia and Vancouver Coastal Health found no differences between 49 patients who had the treatment, called venoplasty, compared with 55 who underwent a sham version of the procedure.
The researchers presented their unpublished results today at the Society for Interventional Radiology's annual meeting in Washington.
"The major finding is that there is no clear benefit early, or within 72 hours or within 48 weeks, of having venoplasty compared with having the sham treatment," said Dr. Anthony Traboulsee, director of the MS Clinic at the Djavad Mowafaghian Centre for Brain Health at the University of British Columbia.
Traboulsee said he hopes the findings will encourage MS patients to consider drug treatments and lifestyle changes such as exercise instead of travelling to other countries for liberation therapy, which can result in complications such as blot clots or damage to the veins. New treatments are on the horizon, he added: "I'm very excited about some of the stem cell [research] going on in Ottawa and Winnipeg."
Multiple sclerosis is an autoimmune disease, in which the body's defence system attacks the protective coating of brain cells, leading to problems with movement, sensation and mental function. MS rates in Canada are among the highest in the world.
Liberation therapy gained worldwide attention in 2009, when Italian vascular surgeon Paolo Zamboni proposed that narrowing of veins in the neck could cause iron to accumulate in the brain and spinal cord, triggering the autoimmune response found in MS. Zamboni referred to it as chronic cerebrospinal venous insufficiency (CCSVI).
Since then, multiple studies have shown that narrowing veins in the neck are common in the general population, and not unique to patients with MS. A 2013 editorial in the British medical journal The Lancet said the evidence should sound a "death knell" for Zamboni's approach.
Nevertheless, patients who have undergone venoplasty have posted videos of themselves online, saying the vein-widening procedure improved their MS symptoms.
Patients who report feeling better after liberation treatment may be experiencing a placebo effect, or a temporary reprieve from MS symptoms, which are known to come in waves, Traboulsee said.
In the Canadian study, all 104 participants had a catheter inserted into their blocked veins. But only 49 had their vessel walls pushed out using a small inflating balloon.
The study was "double-blinded," meaning neither the patients nor the physicians evaluating them knew who received the actual treatment.
A year after the procedure, researchers measured participants using brain imaging, standard assessments of disease symptoms and patients' self-reports. They found no significant differences between the two groups. Patients in both groups reported slight but equal improvements in their symptoms, while physician assessments showed no improvement in either group.
The $5.4-million study was jointly funded by the Canadian Institutes of Health Research, the MS Society of Canada and the provinces of British Columbia, Manitoba and Quebec.
Canadians with MS continue to travel and pay out of pocket for venoplasty, primarily in the United States, said Sandra Birrell, president of the Canadian Neurovascular Health Society, a national charity that promotes CCSVI-related research and education.
Birrell, who has MS, said she had venoplasty at a cost of $5,000 in 2010, followed by a second treatment in 2011 at about double the cost. She said her eyesight improved after the procedures, and she stopped choking several times a day and having bowel spasms.
Even if venoplasty is not a treatment for MS, she said, the procedure may relieve vascular symptoms in people with the disease. She questioned whether the Canadian study evaluated patients' blood flow and overall well-being after the procedure. MRI scans of brain lesions "are not a valid measure of vascular conditions," she said.
Traboulsee said the researchers did measure blood flow but haven't analyzed the data yet. The most important measure of a risky procedure, he said, "has to be the patient benefits." Before embarking on the study, the researchers interviewed more than 100 people worldwide who had undergone liberation therapy. The self-assessment scales they designed for the study included questions about fatigue, pain, "brain fog," vision changes and changes in sensation in hands and feet.
"We weren't out to disprove the [CCSVI] theory," Traboulsee said. "We want to help patients, but we want to help them safely."
Dr. Fabrizio Giuliani, an associate professor of neurology at the University of Alberta, acknowledged that MS may have a vascular component. The question, said Giuliani, who was not involved in the study, "is whether an intervention on the neck veins is going to change that."
He noted that in recent years, fewer of his patients have asked about venoplasty.
Giuliani said he hopes findings from the Canadian study will lead to more investment in other areas of MS research and encourage patients to "move on to the next thing."