Key Words: Closure of patent ductus arteriosus (PDA closure), Amplatzer septal occluder (ASO).
PDA is the fifth or sixth most common congenital cardiac defect observed in most surveys carried out in
different centers of the world1. The incidence of isolated PDA has been estimated at 1:2000 to 1:5000 births
which is about 10 to 12 percent of all varieties of congenital heart disease1, 2. Surgical closure of PDA though long been established, but number reducing gradually as device closure has achieved popularity amongst patient and pediatric cardiologist as a safe and effective procedure. A variety of techniques have been used since 1967 to achieve non-surgical closure of PDA, at present all the pediatric cardiac centers prefer the use of Amplatzer Ductus Occluder (ADO) as the safe and effective one3-10. Catheter Intervention of PDA has now become routine in many centers and can be offered to most of the children and with an isolated ductus as “First choice therapy”. Amplatzer Ductus Occluder is similar in principle to atrial septal defect (ASD) and ventricular septal defect (VSD) devices11. Ductus occluder is used for moderate and large PDAs and detachable coil for small PDAs at the reported center as PDA coil are less expensive and effective in small ones12. In this case, a huge PDA was closed with a non-traditional device (ASD occluder) for the first time without any complications which lead to writing this report.
An 18-year-old male was diagnosed as a case of PDA incidentally when he reported to a family physician for fever 2 years ago. As he was asymptomatic from a cardiac point of view, he never visited any cardiologist for treatment of PDA. For the last 03 months, he was experiencing palpitation and effort intolerance. His physician referred him this time to a paediatric cardiologist for proper management. On examination, loud 2nd heart sound and ejection systolic murmur were noticed. His chest X-ray showed prominent pulmonary conus and ECG showed biventricular
hypertrophy. He had no clubbing and his SaO2 was 96%. So pediatric cardiologist planned for device closure of PDA immediately.
The patient was sedated with Injection Midazolam and Injection Ketamine and was draped properly. A 5
French (Fr) sheath was introduced to the right femoral artery (RFA) and a 6 Fr sheath was introduced to
the right femoral vein (RFV). An Aortogram was done first to locate PDA and to measure its size. Pulmonary
wedge angio showed minimally affected vascular bed. His pulmonary artery pressure was 166/90(70) mm
Hg and pulmonary vascular resistance was 7.5 wood units. Patient was heparinized with 100 u/kg heparin
and introducer sheath was forwarded to descending aorta through the right atrium, right ventricle, pulmonary
artery and PDA with the help of GL catheter and exchange wire. A 16 mm x 14 mm size PDA device was deployed in PDA. Aortogram showed residual shunt. Patient was kept on waiting in the table for one hour to look for any haemodynamic change resulting from the pulmonary hypertensive crisis. No changes was noticed. The PDA device was then taken out through the sheath. An 18 mm ASD occluder was then loaded to the loader and introduced through delivery sheath. Left atrial disc was delivered to the aorta and the whole system was withdrawn to the pulmonary artery. Right atrial disc was released to the pulmonary artery. Device was then deployed by unscrewing. Patient was observed for another half an hour on the table. He was then shifted to the coronary care unit (CCU) and discharged on next morning. Echocardiography on next morning showed no residual shunt. Systolic pulmonary artery pressure was calculated as 45 mm Hg. No evidence of left pulmonary artery stenosis or coarctation of aorta noticed resulting from mechanical obstruction by left or right atrial disc. Injection Ceftriaxone 1 gm was given intravenously at 12 hour interval for 24 hours. Follow-up appointment schedule was given to the patient at 1, 3, 6, 9, 12, 18, 24 months and yearly thereafter for 3 years.
The Amplatzer septal occluder is a percutaneous, transcatheter, atrial septal defect closure device
intended for the occlusion of Atrial Septal Defects (ASD) in secundum position or patients who required
closure of fenestration after a fenestrated Fontan procedure. It is a self expandable double disc device
made from a nitinol wire mesh. Two disc are linked together by a short connecting waist corresponding
to the size of ASD. In the present case, this idea was taken to place the waist of the septal occluder to PDA
and to close its aortic and pulmonary end by the left and right atrial disc respectively. Many options for trans
catheter closure of PDA have been introduced over the last 35 years. The earlier devices have been replaced
by a range of newer and technically superior ones. For PDA closure following options are available:
1. Gianturco coil
2. Detachable coil
3. Riedel coil
4. Grifca bag
5. Amplatzer PDA occluder
7. Amplatzer Septal Occluder (ASO)
For ductus closure, most widely used options at present time are coils and Amplatzer devices. Since the concept of PDA coil occlusion in 1992, several investigators have reported larger series using different techniques with variable results. In 1994, Sommer etal introduced the novel approach of “Snare assistance” in 12 children having PDAs of diameter <3 mm. This technique included introducing the coil into the aortic end of ductus via a retrograde femoral arterial approach and snaring the coil within the main pulmonary artery. To overcome the drawback of various types of devices, both detachable coil (cook) and Amplatzer ductus occluder (ADO) were used in university children Hospital Slovenia and 53 (98%) out of 54 patients had complete closure of the duct. Amplatzer ductus occluder is gaining popularity specially for larger ductus now a day15-18. But there is some ductus which are large in size, tubular and cannot be closed by ductus occluder. Present case was such a case where largest size PDA occluder failed to close the PDA completely and ASD occluder was used as an alternative option. Acute intravascular haemolysis after coil implantation was experienced in four cases in this series19. Coil embolization was experienced in 3 cases in the reported center which were removed with snare catheter and ductus occluder were implanted later in the same sitting.
Coils are primarily applicable for ductus upto 4 mm. But the simultaneous use of multiple coils with the help
of endocardial biopsy forcep would allow coil occlusion of upto 5-6 mm PDA. For larger ductus, grifca bag,
Amplatzer PDA, ASD and VSD (muscular) occluder, the cardio seal may be used. Even tubular PDA can be closed with ASD Occluder. It is now standard practice in many center to recommend non surgical closure as the first choice for most children with PDA. Reported center we prefer catheter closure over surgical ligation and for the last two years, no case of PDA has been referred for surgical ligation. Present case was a challenging case with a huge PDA and severe pulmonary hypertension, where PDA was closed successfully with Amplatzer Septal Occluder.