Transcatheter Interventional Techniques in Pediatric Cardiology - US Cardiology 2006
Usha Krishnan Assistant Professor of Pediatrics, Division of Pediatric Cardiology, New York Medical College, and Attending
Physician and Interventional Cardiologist, Maria Fareri Childrenâ??s Hospital of Westchester Medical Center
Pediatric interventional cardiology was born 40 years ago in 1966, when William Rashkind developed balloon septostomy in neonates with transposition of the great arteries.1 Almost a decade later, Andreas Gruentzig developed coronary angioplasty (between 1972 and 1976), which heralded an explosive era of interventional therapy for adults with heart disease, overshadowing the advances in transcatheter therapy for congenital heart disease.2 However, in the last two decades, development of devices to close septal defects and extracardiac shunts, as well as techniques to open up stenosed valves and vessels, has revolutionized therapy for congenital heart disease. Transcatheter therapy has replaced open heart surgery for simple intra- and extra- cardiac lesions, but surgery still remains a necessity for many complex lesions. Interestingly, instead of developing as competing and conflicting specialties, cardiac surgeons and interventionists have been working together to develop hybrid techniques involving both modalities to improve overall outcomes in children with complex lesions. Recent advances in pediatric cardiology can be broadly subdivided into:
- device closures for septal defects and other vascular structures;
- balloon dilatation of valves, vessels and stenting of narrowed vessels, baffles, and conduits;
- percutaneous transcatheter valve implantation; and
- hybrid techniques involving transcatheter as well as surgical interventions.
Device Closure
The first attempt at device closure of atrial septal defect (ASD) was in 1976, by King and Miller, with limited success and popularity because of the cumbersome technique and use of very large delivery sheaths. In the modern era, the availability of devices with very low profile, ease of implantation, a very high success rate matching surgery with minimal morbidity has made ASD closure an ambulatory procedure, where the patient is discharged home within 24 hours.3 The Amplatzer Septal Occluder is the only device currently approved for ASD closure in the US, but other devices are being used in other countries.Ventricular septal defect (VSD) closure in the US is still not widely approved. The technique for VSD closure is more labor-intensive and requires more training and experience for successful outcomes than with ASDs.4 Both ASD and VSD closures are performed under transesophageal or intracardiac echocardiographic and fluoroscopic guidance. A combined interventional– surgical approach has been used in sick infants with apical muscular VSDs via the right ventricle through a median sternotomy, with improved outcome.5 These patients are poor surgical candidates because of the remoteness of the defect from the surgical field and difficulty in closing them. Closure of patent ductus arteriosus (PDA) has been performed successfully for over a decade using Gianturco coils, and now, with the availability of devices, even large PDAs can be closed easily as an ambulatory procedure with excellent success rates.6 Devices such as coils and detachable balloons have been variably used to occlude other vascular structures like aorto-pulmonary collaterals, arteriovenous malformations, coronary fistulae, Blalock Taussig shunts, and Fontan baffle fenestrations.7
