Building on the Berlin Heart

The team at the Montreal Children’s Hospital did more than save the life of two-and-a-half year-old ƒmile Jutras with their groundbreaking use of the Berlin Heart. They changed the way pediatric specialists now look at life-threatening cardiac cases, opening the door to more heart transplants in the future.

“Waiting for a heart donor in children this young without some kind of bridge like the Berlin Heart is almost impossible – so many of these patients die. Now maybe for some of them, the mechanical heart is an option – or should be an option,” says Dr. Christo Tchervenkov, Director of Pediatric Cardiovascular Surgery at the hospital.

Dr. Tchervenkov, along with Dr. Renzo Cecere, Director of the McGill University Health Centre (MUHC) Centre of Heart Failure and Heart Transplant, and pediatric cardiovascular surgeon Dr. Dominique Shum-Tim, were the three surgeons who guided ƒmile from suspected end-stage myocarditis, through extra-corporeal life support (ECLS), to the Berlin Heart and then finally a heart transplant.

“We’re now in an excellent position if we want to start the first Canadian program, using this device,” said Dr. Tchervenkov, in a recent interview. “If there is another child like him somewhere in Canada right now, we’re ready to take the case tomorrow morning,” says Éric Laliberté, Clinical Leader of Pediatric Perfusion. Indeed, the team of roughly one hundred professionals involved in Émile Jutras’ case now constitutes North America’s largest pool of expertise in pediatric mechanical hearts.

There are only two companies in the world which make mechanical hearts that can be adapted for children – and neither of them have approval for their devices in Canada or the United States.

But even before the Berlin Heart entered the picture, the team at the Montreal Children’s Hospital was already entering new territory. Émile’s case presented challenges from the start. “He came into the ER in congestive heart failure and presumed myocarditis and within a few days he had to be intubated and put on respiratory support. Just days before he had been a normal child with nothing more than an otitis media,” recalls Dr. Marie Béland, Head of Cardiology at the hospital.

The decision was made to put the patient on ECLS, a precedent-setting move, explains Dr. Tchervenkov. “We had agreed on a hospital policy many years ago not to use ECLS for this – as a bridge to transplant – because it is so unpredictable. A patient could wait two or three months for a transplant – and ECLS is both very labour-intensive, requiring 24-hour bedside monitoring, and it has terrible side effects. So our policy has been to use ECLS only for short-term solutions.”

Because there was only a remote chance of recovery in this case, the hospital’s decision to put the patient on ECLS meant a change in policy about using the procedure as a bridge to transplant. “When you commit to bridge to transplant that’s a different philosophy – that means you’re waiting as long as it takes,” says Dr. Tchervenkov. The team expected a one to two week wait to find a suitable donor, and so they embarked on the most ambitious ECLS regimen they had ever undertaken.

“We were very tired,” recalls Éric Laliberté. “There are only two of us [perfusionists] and we don’t do ECLS many times in a year. Although it’s electronic equipment, there’s also a mechanical pump, so if it breaks down you only have four minutes to react before the patient has a brain infarction and dies. One of us had to be at his bedside 24 hours a day.” For seventeen days Laliberté and his colleague pediatric perfusionist Christos Calaritis continued the ECLS – a record length of time for this treatment.

It was a harrowing experience for both the patient, and his caregivers. He required constant anti-coagulation therapy with Heparin to prevent his blood clotting in the equipment, but the side effect of this was bleeding. “He was bleeding from his nose, his mouth, bleeding in his lungs, and from the cannula entry point in his groin. He required more than 300 blood transfusions throughout his hospital stay,” says Laliberté.

The complications on ECLS continued to mount, and still no donor heart was in sight. It was then that the team had “this flash of an idea” – the Berlin Heart. It was an idea that involved getting approval from the Quebec government, and Health Canada, contacting the German company, and getting a crash course in using a device that no-one on the team had ever even seen before.

“The guy arrived from Germany with the Berlin Heart and it was evening. He gave us instructions and we took the patient straight to the operating room – we didn’t have time to go home and rest,” says Laliberté.

In the operating room all three of the hospital’s cardiac surgeons were scrubbed. The patient was taken off ECLS and transferred to a regular cardio-pulmonary by-pass system before being connected to the Berlin Heart. The surgeons inserted four chest cannulas to drain and return blood and connected them to the Berlin Heart, which remained external, being too large to fit inside the child’s chest. After the first 72 hours on the Berlin Heart, Émile no longer needed 24-hour bedside monitoring. For the next 106 days the ICU staff took control.

The field of pediatric mechanical hearts has some striking differences compared to the field of adult mechanical hearts – and caring for a patient on a pediatric device presented some special clinical challenges according to Dr. Shum-Tim.

The design of a child-size pump means many more potential complications because there is less blood volume going through the device, and therefore a need for more pressure. Additionally, the smaller tubes and valves also require more pressure, while at the same time they pose a greater risk of potentially fatal blood clots. However, increased pressure going through the device creates a “shear”effect, causing blood trauma, and damage to the red blood cells, clotting factors and platelets.

“No-one really had any experience in terms of what was the optimal anti-coagulation regimen for Émile. If you over-anticoagulate you have the risk of bleeding, and if you undercoagulate, then there’s the risk of clotting. With children there’s a fine line between the two complications, whereas with adults there’s a much bigger margin to work with,” says Dr. Shum-Tim.

Émile Jutra is thumbs up 15 days after the heart transplant surgery.

Finally, after 109 days on the Berlin Heart – just days short of the record 111 days – a donor heart became available.

“Preparing a patient on a Berlin Heart for the heart transplant was a new experience from an anesthesia perspective,” says Dr. Lavoie. “I was surprised to see how stable he was on the Berlin Heart from a cardio-vascular, hemodynamics point of view – and he was also not intubated. Usually our pediatric patients coming for a heart transplant are very sick, and he was not.”

The transplant procedure took roughly five hours, with no complications.

Recovery and BeyondWithout the Berlin Heart, Émile Jutras could not have survived long enough until a donor heart became available. Now that he has received a heart transplant he faces the same issues and risks as other heart transplant recipients.

“Rejection is the primary concern in the first year post-transplant, and so surveillance is the highest priority,” says Dr. Hema Patel, a pediatrician in the Ambulatory Care Services department. The delicate and sometimes complicated physical monitoring is only part of the follow-up, because the experience has also touched him psychologically. That aspect may prove more difficult to address.

In addition to his medical follow-up, a team of psychologists and therapists will be following Émile and his family long after he is discharged – some of them until he is 18 years old, explains Dr. Patel.