A new minimally invasive technique for repairing the most common cardiac birth defect in extremely premature newborns can be performed safely with a high success rate in babies as small as 755 grams, only a few days after birth, found a Cedars-Sinai clinical study.
A study details the results of a catheter-based approach to repairing patent ductus arteriosus (PDA), commonly referred to as "a hole in the heart."
"If left untreated, PDA can cause heart failure and lifelong complications," said Dr Evan M Zahn, an expert in congenital heart disease and director of the Cedars-Sinai Heart Institute's Guerin Family Congenital Heart Programme. "Current treatment options are not optimal and are fraught with complications."
Before birth, a foetus' blood does not need to go to its lungs to get oxygenated because the mother's own blood circulation supplies oxygen. Key to this process is the ductus arteriosus, a connection between the heart's two major arteries that allows the foetus' blood to bypass its lungs. After birth, however, the baby needs to breathe on its own, so this connection naturally closes. When closure fails, patent ductus arteriosus ensues, leading to difficulty with breathing and feeding, brain haemorrhages and death of premature infants in some cases.
Medication therapy is successful in less than 60% of newborns with PDA and can cause side effects such as kidney failure and bleeding, Zahn said. Surgery has its own short-term risks, and recent evidence suggests that long-term outcomes after surgery for premature babies with PDA may be worse than previously thought.
Zahn, an expert in catheter-based cardiac interventions, and paediatric cardiac surgeon Dr Alistair Phillips, co-director of the Guerin Family Congenital Heart Programme, developed a minimally invasive, transcatheter procedure for premature infant PDA closure. Guided by ultrasound waves, the physician guides a catheter through a vein in the leg to the heart and closes the hole. The procedure can be performed at the bedside in the Cedars-Sinai Neonatal Intensive Care Unit and takes only a few minutes.
In the study, 24 extremely premature infants born at just 24 to 32 weeks' gestation underwent the procedure, which was successful in 21 of the babies. The three babies whose individual anatomy precluded successful closure with the device later underwent successful surgical closure. Because of the fragility of some of the babies in the study, several of the procedures were performed at the patient's bedside instead of an operating room.
"The development of catheter-based procedures for infants is a sea change in the treatment of congenital heart disease," said Dr Eduardo Marbán, director of the Cedars-Sinai Heart Institute. "As Dr Zahn and his team further develop these techniques, parents will no longer have to choose between the risks of surgery and the risks of medications, and babies will get a healthier start in life."
Although PDA usually is diagnosed at birth, some older children and adults have the condition for years before symptoms are noticed and diagnosed, Zahn said. "We can use these same techniques on older children and adults with congenital heart disease," he said. "It is always better for the patient when we can treat a condition without subjecting the patient to the risks and discomfort of surgery."
Abstract
Objectives: The goal of this study was to describe early and midterm outcomes of extremely premature newborns (EPNs) who underwent transcatheter echo-cardiographically guided patent ductus arteriosus (PDA) closure.
Background: Surgical ligation of PDA in EPNs confers significant risk for procedural morbidity and adverse long-term outcomes.
Methods: The Amplatzer Vascular Plug II was used in all cases. Post-ligation syndrome was defined using previously published parameters. Patients were followed at pre-specified intervals, and prospectively collected data were reviewed.
Results: Transcatheter closure was attempted in 24 EPNs (mean procedural age 30 days [range 5 to 80 days], mean procedural weight 1,249 g [range 755 to 2,380 g]) and was successful in 88%. The 3 procedural failures were related to the development of left pulmonary artery (LPA) stenosis caused by the device, and all devices were removed uneventfully. Complications included 2 instances of device malposition, resolved with device repositioning, and 1 instance of LPA stenosis, requiring an LPA stent. There were no procedural deaths, cases of post-ligation syndrome, residual PDA, or device embolization. Survival to discharge was 96% (23 of 24), with a single late death unrelated to the procedure. After a median follow-up period of 11.1 months, all patients were alive and well, with no residual PDA or evidence of LPA or aortic coarctation.
Conclusions: This newly described technique can be performed safely with a high success rate and minimal procedural morbidity in EPNs. Early and midterm follow-up is encouraging. Future efforts should be directed toward developing specific devices for this unique application.
Authors
Evan M Zahn, Daniel Peck, Alistair Phillips, Phillip Nevin, Kaylan Basaker, Charles Simmons, Marion E McRae, Tracy Early, Ruchira Garg
[link url="https://www.cedars-sinai.edu/About-Us/News/News-Releases-2016/New-Nonsurgical-Repair-of-the-Most-Common-Heart-Defect-Found-in-Extremely-Premature-Newborns-Shown-to-Be-Effective.aspx"]Cedars Sinai Heart Institute material[/link]
[link url="http://www.sciencedirect.com/science/article/pii/S193687981631545X"]JACC: Cardiovascular Interventions abstract[/link]