Medical Update: Use of Artificial Lung Saves Toddler
Two-year-old is the first in the U.S. and the youngest in the world to benefit from artificial lung technology.
Physicians at St. Louis Children’s Hospital (SLCH) say Owen Stark, a 2-year-old from Eldon, Mo., is alive today because of an artificial lung. In June, SLCH became the first hospital in the country to use the Novalung® sLA as an artificial lung, and Owen became the youngest person in the world to receive one.
“Owen came to Children’s Hospital in full heart failure due to idiopathic pulmonary hypertension,” says Charles Huddleston, MD, SLCH director of cardiothoracic surgery. “The high blood pressure in his lungs had caused his heart’s right ventricle to become so dilated that it could not contract. In his critical state, we determined he would need a lung transplant to survive.”
As a bridge to transplant, Owen was first placed on extracorporeal membrane oxygenation (ECMO) to give his heart and lungs time to recover and to respond to medical therapy for his pulmonary hypertension. His physicians knew, however, that ECMO was a relatively short-term remedy for Owen’s condition.
“The complication rate for patients on ECMO for five days or less is relatively low, but after two weeks or more, the risk becomes significantly higher,” says Dr. Huddleston. “Problems that develop generally relate to bleeding, infection and damage to other organs, which results in patients becoming ineligible for transplantation.”
By the time Owen reached 16 days on ECMO, his heart had recovered, but his lungs had not. With no organs available and no other options, SLCH’s transplant team, led by Dr. Huddleston, petitioned the Food and Drug Administration (FDA) to secure “compassionate release use” of the Novalung sLA. The sLA is FDA-approved in the United States to help adults through cardiac surgery for intervals of up to six hours, but it is not approved for use as an artificial lung. Dr. Huddleston recognized that the sLA device might provide Owen the same lung benefits as ECMO but with fewer potential complications.
“The Novalung has a number of advantages over ECMO while serving the same function. ECMO requires a pump to move the blood through oxygenation. The Novalung uses the patient’s own heart to do the respiratory work, which makes the exchange of oxygen and carbon dioxide more efficient,” says Dr. Huddleston. “On ECMO, a patient has to be sedated or use a ventilator, which is not the case with the Novalung. Patients are able to eat, communicate and even get out of bed and walk around. Basically, the artificial lung gives patients more freedom to rehabilitate from a severely debilitated state to one that’s more normal.”
The FDA agreed to the conditional use of the Novalung sLA for Owen as a bridge to transplant, as did the Institutional Review Board that oversees St. Louis Children’s Hospital and Washington University School of Medicine. Once Owen was on the artificial lung for a while, however, his condition began to improve.
“Owen developed little clots inside one of the tubes connecting the Novalung to his heart. Every other day, I needed to change that tube, which required clamping the device so that he was off of it completely for about 90 seconds,” explains Dr. Huddleston. “The first four or five times I did this, his blood pressure and oxygen levels dropped significantly. Over time, however, this improved to the point where his blood pressure and oxygen hardly dropped at all. It became apparent that the aggressive treatment he was receiving with pulmonary hypertension medications was helping his lungs to recover appreciably.”
The proof of Owen’s recovery came on his 23rd day on the sLA, when he accidentally kicked off one of the device’s connector stopcocks. Expecting to have to reconnect Owen to the artificial lung, his physicians found that Owen’s lungs were strong enough to function on their own. Instead of the sLA serving as a bridge to transplant, it had served as a bridge to getting him on medical therapy.
“Although pulmonary hypertension is a disease that does not have a cure at this point, it now can be palliated with medications fairly effectively,” says Dr. Huddleston. “In the past we did at least one transplant per year in children with the disease. In contrast, over the past five years we’ve only done one transplant. That improvement is because of the medical management that is now available.”
Despite the advances in medications, Dr. Huddleston says an average of two patients a year die at SLCH because of pulmonary hypertension, and these are the cases most likely to benefit from use of the Novalung sLA.
“The first scenario is children like Owen—they haven’t been diagnosed with the disease, it progresses to the point where the heart can’t function, and we can’t get them better,” says Dr. Huddleston. “The second scenario is patients who are listed for lung transplantation but are being well managed with medications until an abrupt change occurs in their health, such as developing pneumonia. In these two situations, the Novalung could stabilize the patients’ health until transplantation or until medications gradually reverse the disease process and they recover as Owen has.”
Owen was released from SLCH on September 9. Although he will continue to return to SLCH for follow-up evaluations for many months to come, Owen has benefited from two of St. Louis Children’s Hospital’s greatest strengths: access to advanced technology and knowledgeable physicians with expertise in treating seriously ill children.
