New Therapy for PDA Closure in ELBW Infants

A new therapy is now available at Children’s Hospital of Philadelphia (CHOP) for patent ductus arteriosus (PDA) closure in extremely low birth weight (ELBW) infants. PDA is one of the most common congenital heart defects occurring in premature babies. It occurs when the ductus arteriosus—a blood vessel in the fetal heart that is supposed to close after birth—remains open. As a result, babies have difficulty breathing normally due to increased blood flow to the lungs. While small PDAs often close on their own, a large PDA can lead to life-threatening problems.

Until recently, only two devices approved by the U.S. Food and Drug Administration (FDA) existed to “plug” holes in the heart for pediatric patients. Neither was small enough to help extremely premature newborns.

Recognizing the need for a new way to help ELBW babies born with PDA, clinicians at CHOP participated in a multicenter non-randomized clinical trial of the Amplatzer Piccolo Occluder (Piccolo device). This trial was designed specifically to test the safety and efficacy of catheter-based PDA closure in ELBW infants. CHOP was a leading enrolling center in this important study, which led to FDA approval of the Piccolo device in January 2019.

The Piccolo device—a self-expanding wire mesh device that is smaller than a pea—has a tri-lobed nitinol mesh design, configured specifically for the typical PDA morphologies encountered in ELBW infants. It is delivered into the PDA via venous access, using a combination of echocardiographic and fluoroscopic guidance. Arterial access is not required.

The pivotal trial testing the safety and efficacy of the device began with 50 patients who were older than 3 days at 8 centers across the U.S.; thereafter, an additional 150 patients were enrolled in the continued access phase of the trial, which ended in February 2019 (following FDA approval). One hundred of these patients were <2kg in weight at the time of the procedure, with the majority between 700 and 1000 grams. Successful implant was obtained in 99/100 patients, with low morbidity and zero procedural mortality.

To date, we have treated dozens of ELBW infants using the Piccolo device with outstanding results. As one of the initial trial centers, we have more experience than anyone in the region in treating these complex, fragile infants with PDA. Our neonatologists worked with cardiologists in our Cardiac Center to refine the procedure and collaborate on the treatment.

Catheter-based PDA occlusion represents a revolutionary advance for the very smallest premature infants who require corrective treatment for this condition. It offers clear benefit over the traditional approach via thoracotomy, minimizing secondary complications such as vocal cord nerve injury, diaphragm nerve injury, lung collapse, rib injury, long-term scoliosis, vascular complications, and death. It also minimizes postoperative pain and allows for faster recovery. Babies are often able to be weaned from artificial respiratory support sooner and can be transferred back to their referring hospital—and closer to home—as early as 24 hours. In the event that a PDA is unable to be closed with this technique, we have instant access to a surgical team that can proceed with open ligation via thoracotomy.

Case study

One patient in the trial weighed less than 3 pounds. When doctors at CHOP saw she was too small to be treated using established devices, which are designed for larger patients, they advocated for her to be included in the FDA trial and treated with the Piccolo device. The procedure went smoothly, and the baby is now home with her family and thriving.

The baby was born in fall 2018 and transferred to CHOP’s Newborn/Infant Intensive Care Unit (N/IICU), where she was subsequently diagnosed with patent ductus arteriosus (PDA).

Neonatologist Janet Lioy, MD, examined the baby and saw that her PDA was not closing on its own. Lioy thought the baby might be a candidate for the Piccolo device, a new tool delivered by cardiac catheterization that was in clinical trials at CHOP. Lioy asked interventional cardiologist Matthew J. Gillespie, MD, to review the baby’s case. Gillespie reviewed the case and found that the baby met the criteria for the clinical study and was a good candidate for the Piccolo device. Gillespie talked to the baby’s family about participating in the trial. The baby would be among the first at CHOP to receive this new device. If the device couldn’t plug the hole, the baby would likely need surgery to fix it. The family agreed to try the interventional cardiac catheterization procedure.

During the procedure, a catheter was placed in the baby’s leg near her groin area and fed up through her veins to her heart. The device was expertly placed into the PDA, eliminating the troublesome left-to-right shunt. The procedure took less than an hour and required minimal anesthesia. After the procedure, the baby was returned to the N/IICU, where she recovered quickly. It was immediately apparent that she had more energy; she could eat for longer and began to gain weight; and she achieved developmental milestones. She remained in the hospital for a few weeks, and was then released home.

Now, months after the procedure, the baby is healthy. She is meeting milestones based on her adjusted age. She returns to CHOP Cardiology for regular follow-up, but should not need further intervention in the foreseeable future.