Mariam Tannous with her physicians, Dr. Osami Honjo and Dr. Aamir Jeewa at Sick Kids Hospital in Toronto.Supplied
At 11 years old, Mariam Tannous has experienced many uncommon things for someone her age. She has undergone multiple open-heart surgeries – two of which resulted in a heart transplant – and, just last year, became both one of the youngest patients in the world and the first child in Canada to receive a fully artificial heart.
Now, a full year after the surgery was completed, Mariam’s family and her team of doctors at Sick Kids Hospital in Toronto are sharing their experience with the life-saving technology.
“It’s been so difficult,” Mariam’s mother, Linda Antouan Adwar, said of Mariam’s long battle against congenital heart disease. “I understand some parents feel they can’t continue, but my message for them is: Don’t give up.”
So-called total artificial hearts like Mariam’s are not replacements for normal hearts. Rather, such devices are seen as a type of “bridge” therapy for patients who require heart transplants but are not candidates for one, either due to a lack of donors or because they are simply not healthy enough to undergo a transplant.
In Mariam’s case, she required a re-transplantation, which is considered highly risky for someone of her age, especially with an already-weakened immune system due to the immunosuppressive drugs she had been taking to maintain her existing transplanted heart.
With Mariam’s heart failing and no other options available, Dr. Osami Honjo and his surgical team decided to attempt the difficult operation of installing an artificial heart, hoping the device could give her body’s immune system the chance to calm down prior to a second transplant procedure.
“Either we gave up and let it be, or we had to do something,” said Dr. Honjo, adding that his team accepted the challenge of the procedure while knowing that her two previous procedures would mean they would be contending with an already fragile body.
Mariam receives physical therapy after receiving the total artificial heart.Courtesy of Family
“We were anticipating that this operation was going to be very difficult because we knew that, inside the chest, it was going to be really messy.”
The surgery to install a SynCardia Total Artificial Heart in Mariam’s body, where it would remain for the two months before she was able to receive a full heart transplant, began on July 8, 2021 and lasted some fourteen hours.
During the operation, Mariam’s surgical team removed the bottom half of her heart and replaced its valves and outer structure with a polyethylene replica – all while keeping a normal level of blood flow to the rest of the body and organs.
Despite the complexity of the operation, Dr. Honjo said the main problem that occurred during the surgery was the actual size of the device. Since it only came in two sizes, both of which were too big for Mariam’s body, the surgical team were unable to close Mariam’s chest for five days following the surgery until her swelling subsided.
Dr. Aamir Jeewa, Mariam’s cardiologist and the head of heart function at Sick Kids, described the pumps of an artificial heart as being like “two grapefruits.”
“The majority of mechanical support for children with heart failure are in the form of devices approved for adult-sized patients,” Dr. Jeewa added. “This often creates challenges trying to fit these larger devices in smaller children.”
When Mariam eventually awoke from the operation, two tubes ran from the device inside of her body out of two holes in her abdomen to a piece of large external machinery that regulated her heart’s rhythm and allowed the device to replace the functionality of her two ventricles.
Mariam at a follow-up appointment earlier this year.Supplied
Just over two months later, in September, Mariam underwent her fourth open-heart surgery and received her second heart transplant – the same one beating inside of her today.
“She loved life and she needed to be alive,” said Ms. Adwar.
“She goes to school in person after all this. She goes to the swimming pool again and swims with her brother and her dad. She got to play basketball again, go running around, use the bike. She does everything now, thank God.”
Dr. Honjo and Dr. Jeewa both said that they expect technologies like the total artificial heart to continue to improve and become smaller, allowing easier use in children such as Mariam.
Whether artificial hearts will one day replace the need for transplantation entirely remains to be seen, but Dr. Honjo said – given the advancement in biotechnology in the last two decades – that it is a real possibility.
“20 years ago we didn’t have this type of technology at all, so this is a very rapid and quite significant development in recent years,” he said.
“We’re not there yet, but it’s possible.”
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