The Montreal Children's Hospital, which forms part of MUHC, is only the fifth centre in the world certified to perform the procedure, developed by Dr. Philippe Bonhoeffer at Great Ormond Street Hospital in London. Montreal cardiologists Giuseppe Martucci and Adrian Dancea went to Britain last year to learn the procedure.

It's not known how long the replacement valves will last, as the procedure itself is only four years old. The percutaneous implant method means the risk of death associated with heart malformations will be reduced, Dancea said.