She is one of a handful of people in North America whose hearts have regained the capacity to pump blood through their bodies, cardiologist Ivan Rebeyka said at a news conference Wednesday at the Stollery Children's Hospital in Edmonton, the province's capital.
The teenager received the artificial heart on Aug. 30, 2006, after her kidneys and lungs began to shut down. Months before that, the Grade 8 student had suffered a bout of the flu, and a virus had moved along a deadly path into her heart, enlarging the organ to the point where it couldn't pump properly.
Doctors feared she would die, and she was moved to the top of the North American donor list for a heart transplant.
Soon after the artificial heart was implanted, Dr. Rebeyka said, doctors noticed Melissa's own heart was trying to take over when the artificial heart was periodically turned down.
"We were still planning a heart transplant when we noted that her own heart seemed to be getting stronger and stronger as the weeks passed," he said. "At first, the Berlin Heart was turned down for short periods, then for longer and longer as we watched the heart to make sure it could do its job."
The artificial heart worked to keep the teenage girl alive while her own heart healed, Dr. Rebeyka said.
The Berlin Heart was removed in January, and Melissa was out of the hospital and back in her home in Canmore, in southern Alberta, two months later.
Berlin Heart is the name of a company in Berlin, Germany and also of a ventricular assist device it makes. The device works by helping the right ventricle of the heart to pump blood to the lungs and the left ventricle to pump blood to the body.
It comes in various sizes for a range of patients, including newborn babies. The bulk of the device is extracorporeal (outside the body). Only the tubes are implanted. They emerge from small openings to enter the pump, a small round chamber. The system is run by a laptop computer. The Berlin Heart is intended to be used as a bridge to recovery or as a bridge to a transplant.
Melissa remembers her thoughts when doctors told her that her heart was recovering: "Wow! Now I get to keep my own and I don't have to go through all that stuff that the transplant people have to."
After five months, she'd grown used to hauling around the external device with its long hoses and an external pump. She bought clothes that were too big because of all the dressings and tubing and the device itself. She found a dress for a dance last December, although a hose peeped out from the bottom.
Without the artificial heart, she's more comfortable, although she remains self-conscious about her surgery scars.
"It's easier to shower," Melissa said.
Still she seemed to feel a sense of gratitude for the Berlin thing.. "I wish I could keep it ... it saved my life and it means so much to me," she said as she clasped the plastic-and-metal device in her hands.
She must return the "heart" to the Berlin Heart program at the Stollery Children's Hospital, where it will likely be used for training purposes.
Last fall, the hospital became North America's first training and support centre for the world's first mechanical heart designed for children.
It's been a tumultuous journey for Melissa's mom, Sharon Mills.
"When they first thought that her heart was beginning to heal, it was something you were scared to hope for," she said.
Thrilled that her daughter was healing, but terrified at the thought the girl's own heart might not be strong enough to let her survive, Ms. Mills stayed by her daughter's bedside morning and night.
"We still think of it as a day-by-day thing. As long as she does what's expected of her, we think she'll be okay," she said.
Ms. Mills said she's turned into a hyper-vigilant parent, overprotective of her daughter after months of fighting to keep her alive.
The true test came during a shopping trip to West Edmonton Mall on Monday, when Ms. Mills agreed to let Melissa visit the washroom on her own. "I was pacing a little bit until she got back," she said. "I'll get used to that."
Last fall, Stollery Children's became the first North American centre to provide training about the device, made by German-based Berlin Heart Inc., for physicians in other facilities across Canada, the United States and South America.
Hospital officials say about 300 patients worldwide, including about 100 in North America, have the device.