Canadian doctors say they have performed the country's first surgical treatment to control high blood pressure -- a technique they say could offer an important new way to help some 250,000 people for whom hypertension medications don't work.

Doctors at the Peter Munk Cardiac Centre in Toronto performed what's called a "renal denervation" Tuesday morning on a 57-year-old man, whose high blood pressure defied control with the usual drugs.

"He is doing well," Dr. Dheeraj Rajan, medical imaging specialist at the centre, told CTV News, adding, "We have seen a reduction in his blood pressure."

The procedure was first developed in Australia. Doctors placed tiny burns on a nerve that controls the arteries that feed blood to the kidneys, which play a role in setting the body's blood pressure. When the nerve is deactivated, it results in a drop in blood pressure.

About one in 10 patients with hypertension cannot control the condition with medication or cannot tolerate the drugs, leaving them at greater risk of heart attacks and strokes.

Studies have suggested the procedure can cut their risk of these serious side-effects by half, because the technique lowers their blood.

One study found that after six months, 39 per cent of patients receiving renal denervation had lower target blood pressure and, overall, 50 per cent of patients showed a measurable benefit from the intervention. Systolic blood pressure fell an average of 32 mm Hg and diastolic blood pressure fell an average of 12 mm Hg.

The effects appear to last at least two years in the patients studied for the longest period of time.

Some doctors call it a potential "cure" for hypertension in some patients, in that some patients no longer require medical treatments -- though that claim requires more scientific validation.

While the procedure so far has proven relatively safe, there are long-term questions that need to be answered.

"When you heat up the artery and kill the nerves it is possible at least theoretically that you could damage the artery, so we have to watch the arteries over the long term," said Dr. Barry Rubin, medical director at the Peter Munk Cardiac Centre. "So we have to do a long-term analysis to determine if this is beneficial overall or do the risks outweigh the benefits."

The hospital received approval to test the novel treatment under Health Canada's special access program for patients who have life-threatening conditions, and who have no other treatment options.

The Toronto hospital plans to treat more patients with this surgical technique, studying its safety and effectiveness.

The procedure offers the tantalizing possibility of a one-off treatment for hypertension. It has not yet been studied in less severe hypertension, though researchers believe it may be used in other less severe cases, weaning patients off drugs.

The Toronto team was led by Rajan, who is the interventional radiology specialist at Toronto General hospital. His team recently returned from Germany, where they trained for the procedure. Germany has already approved the use of renal denervation to treat selected patients with hypertension.

With a report from CTV's medical specialist Avis Favaro and producer Elizabeth St. Philip