The results of the small, observational study were announced Wednesday in St. John's by lead investigator Dr. William Pryse-Phillips, a professor emeritus of neurology at Newfoundland's Memorial University.
Pryse-Phillips said he had gone into the study hopeful the treatment might have something to offer his MS patients, but completed it convinced the people who had the vein-opening procedure didn't experience any gains.
"I am disappointed. I had hoped. I cannot recommend this therapy on the basis of these results at this time," he said during a news conference, the video of which is posted on the Department of Health and Community Service's website.
The province spent $400,000 on the study, which compared 30 patients with MS who had travelled outside the province to have the therapy and 10 who did not. Participants were subjected to an array of tests before the treatment and then at intervals of one month, three months, six months and one year post-procedure.
It was an attempt to test a theory that has driven a wedge between MS patients and the neurologists and professionals — including those at the MS Society of Canada — who work to advance the cause of MS sufferers.
The theory hails from Italy. Dr. Paolo Zamboni, a vascular surgeon from the University of Ferrara, has hypothesized that MS is not a neurodegenerative disease, as has been thought, but a disease resulting from collapsed veins in the neck and upper chest. He named the condition chronic cerebrospinal venous insufficiency, or CCSVI.
Blockages in the veins of MS patients prevent blood from draining properly from the brain, and the pooled iron-rich blood damages brain tissues, Zamboni suggests. He says opening those blockages with the balloon procedure used to repair clogged arteries — angioplasty — offers substantial benefit to MS patients. (When applied to veins, the procedure is called venoplasty.)
Zamboni's theory has taken off, particularly in Canada.
While clinicians here do not do the unproven procedure, scads of MS patients have travelled to the U.S., Eastern Europe, and India to have their veins opened. And enormous pressure has been placed on the federal and provincial governments, both to fund clinical trials and to include the treatment in the items covered by provincial health-care programs.
Newfoundland and Labrador Health Minister Susan Sullivan said based on the findings of Pryse-Phillips' trial, her province will not be covering the cost of CCSVI treatment going forward.
Dr. Andreas Laupacis, who has been periodically assessing the scientific evidence for and against the CCSVI theory for the Canadian Institutes of Health Research, said the study has some strengths and some weaknesses.
If the patients who didn't have venoplasty had been given a sham procedure — the equivalent of a placebo in this setting — the results would have been stronger, for instance.
"I think it's another piece of evidence," said Laupacis, who is executive director of the Li Ka Shing Knowledge Institute at St. Michael's Hospital in Toronto.
"It's certainly every bit as good a negative bit of evidence as the positive bits of evidence that people on the other side are hauling out.... But I don't think it's conclusive."
Pryse-Phillips said the study was set up so that he didn't know which participants had undergone venoplasty and which had not. That is done so any inherent biases a researcher might have cannot influence his or her appraisal of how well an intervention has worked.
The study participants were assessed using a combination of tests — questionnaires which the patients filled out, MRI scans of their brains, and a standardized test used to gauge function in MS patients. Those tests looked at manual dexterity, ability to walk and mental acuity.
Pryse-Phillips said he saw no differences among the patients, even though those who had received the therapy reported positive results in the questionnaires — things like they felt they had more energy or their balance was better.
He noted, though, that even the self-reported gains seemed to tail off over time, with a drop-off after the three-month check up.
Laupacis found that interesting.
"It could certainly totally be a placebo effect, the fact that it goes away in three months. On the other hand, without a kind of control group, you can't be 100 per cent sure."
Pryse-Phillips also noted that by the 12-month check up, about a quarter of the patients who had undergone venoplasty had blocked veins — either a clot in or the closure of one or more neck veins. But there was no difference, function-wise, in these patients as compared to the 75 per cent who didn't have the clots or blockages.
Pryse-Phillips said under Zamboni's theory, those who experienced the closures should have had poorer results than those who didn't.
Note to readers: This is a corrected story. A previous version misspelled Zamboni's first name.