'Mechanical bridge' takes Dallas girl to life-saving heart transplant

By Katherine Morales

At a recent checkup, Alexis Miller (center) huddles with cardiologist Dr. Aliessa Barnes (left), assistant professor of pediatrics, and Susan Daneman, heart transplant coordinator at Children's Medical Center Dallas.

Leticia Lopez had every reason to believe that her daughter was in perfect health. In early 2008, Alexis Miller was nearing the end of second grade at a Dallas elementary school. She participated in sports, played vigorously with her younger brother, Givonn, and rarely got sick.

But after a seemingly innocuous cold, Alexis was diagnosed with cardiomyopathy — a devastating illness that inflamed her heart muscle and prevented it from pumping blood efficiently.

“I really didn’t believe them. I kept telling the doctors that I thought they had to be wrong about it,” Mrs. Lopez said. “It happened so fast. She had a little cold and said she felt really tired, but she wasn’t running a temperature or anything like that.”

Doctors surmised that Alexis had become infected with a virus that attacked her heart muscle, but they told her family there was no way to know for certain.

Alexis was admitted to Children’s Medical Center Dallas, where her mother stayed at her bedside every hour that she wasn’t working. After Alexis was placed on the heart transplant list, the family had to wait and watch as the girl’s condition worsened to the point that she had to be intubated. Time was running out.

Dr. Kristine Guleserian, Alexis’ surgeon and an assistant professor of pediatric cardiovascular surgery at UT Southwestern, knew the challenges the little girl faced.

Dr. Kristine Guleserian

“There is an average waiting time of about 2½ months for a donor heart,” Dr. Guleserian said. “The challenge is keeping a patient as healthy as possible while they wait for the heart.”

Children who are in extreme heart failure may be placed on extracorporeal membrane oxy­ge­na­tion, a technique that provides both cardiac and respiratory support oxygen when the heart and lungs are so severely diseased or damaged that they can no longer function. But it’s not meant for long-term life support, and the patient must remain on a ventilator.

Luckily for Alexis, a new device called the Berlin Heart became available. The Food and Drug Administration has not yet approved the device, but a pilot study is under way, and the Division of Pediatric Cardiothoracic Surgery at UT Southwestern is one of a handful of sites in North America currently implanting the Berlin Heart on a compassionate-use basis. It is hoped that the device will soon be approved for more widespread use.

“Currently the only approved ventricular assist devices are designed for adults or larger children. The Berlin Heart is much smaller and has been spe­cifically designed for children and infants,” Dr. Guleserian said. “So we implanted Alexis, and she did beautifully.”

The device enabled the girl’s diseased heart to pump blood more efficiently, serving as a “mechanical bridge to transplant,” Dr. Guleserian said.

Alexis was able to resume a some­what normal life — even playing whiffle ball in the cardiovascular intensive care unit — until June, when she was trans­planted successfully with a new heart. She is now 8 years old, and her life has changed dramatically.

Alexis recently went for a bike ride around her neighborhood with her dad, and she is back in school, where her favorite subject is math.

“I tell her that this heart is a gift,” Mrs. Lopez said, “and we need to do everything we can to keep it healthy.”