What is the recommended treatment for a pediatric patient with an atrial septal defect (ASD)?

Treatment of Atrial Septal Defect in Pediatric Patients

For pediatric patients with hemodynamically significant secundum atrial septal defects (ASDs) and suitable anatomy, transcatheter device closure is the indicated treatment of choice, offering comparable outcomes to surgery with lower morbidity. 1

Treatment Selection Algorithm

Class I Indication: Transcatheter Closure

• Hemodynamically significant secundum ASD with suitable anatomic features is a Class I indication for transcatheter closure 1
• Hemodynamic significance is defined as: evidence of right-sided heart volume overload, right-sided heart failure, and/or elevation of right-sided heart pressures secondary to left-to-right shunting 1
• Suitable anatomy requires adequate septal rim surrounding the defect to ensure device stability, appropriate patient size, and no interference with vital cardiac structures (atrioventricular valves or pulmonary veins) 1

Class IIa Indications: Reasonable to Perform Transcatheter Closure

• Patients with transient right-to-left shunting who have experienced paradoxical emboli (stroke or recurrent transient ischemic attack) 1
• Patients with transient right-to-left shunting who are symptomatic from cyanosis and do not require the communication to maintain adequate cardiac output 1

Class IIb Indication: May Consider Transcatheter Closure

• Small secundum ASD in patients at risk of thromboembolic events (transvenous pacing system, chronically indwelling intravenous catheters, hypercoagulable states) 1

Class III: Contraindications to Transcatheter Closure

• Small secundum ASD with no hemodynamic significance and no other risk factors 1
• Non-secundum ASDs (septum primum defects, sinus venosus defects, unroofed coronary sinus defects) - these require surgical repair 1
• Advanced pulmonary vascular obstructive disease 1

Device Options and Technical Considerations

Available Devices in the United States

• AMPLATZER septal occluder: Nitinol wire mesh with Dacron fabric, suitable for all secundum ASD subtypes, can close defects up to 38 mm diameter 1
• HELEX septal occluder: Single nitinol strand with microporous expanded polytetrafluoroethylene, suitable for small-to-moderate defects (≤18 mm diameter) 1

Patient Size Considerations

• Common practice suggests weight ≥15 kg offers technical advantages and simplifies the procedure 1
• Children as young as 2 years of age can undergo device closure 1
• Recent evidence demonstrates that transcatheter closure in infants <15 kg is feasible and safe with comparable complication rates to larger children 2
• For very small infants with large ASDs (device/weight ratio ≥1.5), transcatheter closure is feasible in symptomatic patients with acceptable complication rates 3

Mandatory Periprocedural Anticoagulation Protocol

At Time of Implantation (Class I)

• All patients must receive at least 100 U/kg UFH (up to 5000-U maximum dose) at the time of device implantation 1, 4

Post-Implantation Antiplatelet Therapy (Class I)

• Children must receive oral antiplatelet therapy with low-dose aspirin for at least 6 months after implantation 1, 4
• The 6-month duration is based on the time required for complete device endothelialization 4
• If residual defect persists after device implantation, many clinicians continue thromboprophylaxis beyond 6 months due to ongoing paradoxical embolus risk 1, 4

Additional Anticoagulation (Class IIb)

• For older children and adults, another anticoagulant may be considered in addition to aspirin for 3-6 months after implantation 1, 4

Complications and Risk Profile

Major Complications (1.6% rate with AMPLATZER)

• Device embolism requiring surgical removal 1
• Cardiac arrhythmia requiring major treatment 1
• Cerebral embolism 1
• Cardiac erosion/perforation leading to tamponade and death - most severe late complication 1, 5
• Atrioventricular block 1

Minor Complications (6.1% rate)

• Cardiac arrhythmia requiring minor treatment 1
• Thrombus formation 1
• Device embolism with percutaneous removal 1
• Wire-frame fracture with HELEX device (5-7% incidence, typically without clinical sequelae) 1

Long-Term Complications

• Device thrombosis and cardiac erosion are the most severe late complications 5
• Atrial arrhythmias are the most common late complication 5
• Other delayed complications include nickel allergy, cardiac conduction abnormalities, valvular damage, and device endocarditis 5

Surgical Closure Indications

Surgical closure remains the therapeutic option of choice for:

• Neonates and infants <2 years of age 1
• Non-secundum ASDs (septum primum, sinus venosus, unroofed coronary sinus) 1
• Secundum ASDs with unsuitable anatomy for device closure 1
• Failed transcatheter closure attempts 1

Critical Pitfalls to Avoid

• Never omit procedural UFH anticoagulation - this is a Class I recommendation with mandatory 100 U/kg dosing 1, 4
• Never discontinue aspirin before 6 months unless compelling contraindications exist, as complete endothelialization requires this duration 4
• Never attempt transcatheter closure in patients with advanced pulmonary vascular obstructive disease - this is a Class III contraindication 1
• Never use current devices for non-secundum ASDs - these anatomic variants require surgical repair 1
• Do not assume small patient size is an absolute contraindication - recent evidence supports device closure in symptomatic infants <15 kg when clinically indicated 3, 2

Outcomes and Follow-Up

• Transcatheter closure demonstrates comparable outcomes to surgical closure in carefully selected patients 1, 6
• Device closure is associated with low complication rates, short anesthetic times, and short hospitalizations 1
• Complete closure rates are high with minimal residual shunts at 6-month follow-up 7
• Symptoms resolve completely or improve significantly in symptomatic patients 7
• Patients with failure to thrive gain weight appropriately after closure 7