New Canadian research has documented complications in some MS patients who have travelled abroad to undergo a controversial treatment for their illness, but the complications appear to arise from the use of stents -- something not advised by the therapy's creator.

Researchers at the University of Calgary followed five patients who had undergone the so-called "liberation therapy," a treatment for MS developed by Italian researcher Paolo Zamboni. Zamboni believes the disease is caused by a narrowing of the vessels that drain blood from the brain, a condition called chronic cerebrospinal venous insufficiency, or CCSVI.

The condition allows for iron deposits to build up on the brain, Zamboni says, which leads to debilitating symptoms.

Zamboni's research has shown some patients are relieved of their symptoms after having balloons inflated, to open the narrowed veins, and then removed. However, other studies have not found a link between CCSVI and MS and have reported that patients who are treated for CCSVI suffer from a variety of side effects and complications.

Zamboni urged against the use of stents to widen the veins of MS patients, but some medical centres abroad do not follow his advice.

In their study, the Calgary researchers reported complications in the five patients, including:

• Internal jugular vein stent thrombosis
• Cerebral sinovenous thrombosis
• Stent migration
• Cranial nerve injury
• Injury associated with venous catheterization

The researchers conclude that evidence of the risks associated with the treatment is growing just as the debate over whether CCSVI plays a role in MS continues.

"As increasing numbers of MS patients are seeking such procedures, these five cases represent the beginning of a wave of complications for which standardized care guidelines do not exist," the authors write. "Our experience and that of our colleagues will be used to develop guidelines and strategies to monitor and manage these patients as their numbers increase."

The findings are published in the Canadian Journal of Neurological Sciences.

Walter Stefanuk of the group CCSVI Alberta dismisses the study, saying "it's more of an opinion piece than anything. And quite frankly I think it's a bit of fear-mongering."

Stefanuk and the group are challenging the study. He admits liberation therapy isn't perfect, but says his sister had the treatment and he would too.

"My sister is 100 per cent better," he said.

Stefanuk also noted that complications are rare, given the number of people who have undergone the therapy.

Other studies have not found a link between CCSVI and MS and report that patients who are treated for the latter suffer from a variety of side effects and complications.

The news of Zamboni's theory sparked demands among Canadian MS patients that the treatment, dubbed the "liberation therapy," be offered to patients in this country. In June, Health Minister Leona Aglukkaq announced that the federal government will fund clinical trials into the therapy.

In the meantime, Canadian patients have travelled overseas for treatment, which has raised fears among some doctors that the patients are not receiving adequate follow-up care.

In an editorial accompanying the Calgary study, neurologist Dr. Marcelo Kremenchutzky of the London Health Sciences Centre, points out that a lack of follow-up care means complications may go under-reported or "misclassified, so the risk/benefit profile of endovascular procedures for presumed venous stenosis in MS patients remains unknown."

He cites data from Poland that showed a variety of complications, from gastrointestinal hemorrhage to stent migration, as well as Bulgarian data that found complications such as ruptured veins and cardiac arrhythmias.

Kremenchutzky points out that as the controversy swirls around CCSVI and the so-called "liberation therapy," patients are still looking outside Canada for treatment while their doctors are developing methods to manage potential complications once they return home.

"While the debate continues, and science runs its course, Burton et al remind us that these procedures are not without risk," he writes, "and that follow-up care should focus on identification of potential complications, as it is the duty of the treating physician to identify, investigate, and mitigate such risks while maximizing benefits."