What is the safest method for atrial septal defect (ASD) closure in a 4-year-old with Noonan syndrome, open heart surgery or catheter-based closure?

Surgical Closure is the Safest Method for ASD Closure in a 4-Year-Old with Noonan Syndrome

Open heart surgical closure is the safest method for atrial septal defect (ASD) closure in a 4-year-old with Noonan syndrome due to the specific anatomical and clinical considerations associated with this genetic condition.

Rationale for Surgical Approach

Guideline Recommendations and Considerations

The American Heart Association guidelines provide clear direction regarding ASD closure methods:

• Transcatheter closure is indicated for secundum ASDs with suitable anatomic features 1
• Surgical closure is recommended when the anatomy of the defect precludes the use of a percutaneous device 1
• Certain ASD types (sinus venosus, coronary sinus, and primum defects) are not amenable to device closure 1

Noonan Syndrome-Specific Considerations

Noonan syndrome presents unique cardiac challenges that favor a surgical approach:

1. Associated cardiac abnormalities: Noonan syndrome commonly presents with hypertrophic cardiomyopathy along with ASDs 2, creating a more complex cardiac anatomy that may be better addressed surgically

2. Anatomical variations: Patients with Noonan syndrome may have atypical septal anatomy or deficient rims that make device closure technically challenging or impossible

3. Risk of complications: The presence of hypertrophic cardiomyopathy increases the risk of device-related complications such as obstruction or erosion

Device Closure Limitations

Several factors limit the applicability of transcatheter closure in this case:

• Size constraints: While device closure can be performed in children under 4 years, success rates are lower with larger defects relative to patient size 3

• Device-related complications: Potential complications include:

  • Device embolization (occurs in approximately 0.55% of cases) 4
  • Cardiac wall erosion (a potentially catastrophic complication) 5
  • Device migration requiring retrieval (which can be technically challenging in small children) 4

• ASD size-to-weight ratio: An ASD size-to-patient weight ratio >1.2 is associated with failure of the percutaneous approach 3

Benefits of Surgical Approach

• Complete visualization: Surgery allows direct visualization of the defect and any associated abnormalities

• Definitive repair: Surgical closure eliminates the risk of residual shunting (seen in up to 44% of device closures initially) 5

• Clinical improvement: Early surgical closure in symptomatic young children has demonstrated significant clinical improvement, particularly in those with underlying pulmonary abnormalities 6

• Ability to address multiple issues: Surgery can simultaneously address the ASD and any other cardiac abnormalities common in Noonan syndrome

Decision Algorithm

1. Determine ASD type: If non-secundum ASD (primum, sinus venosus, or unroofed coronary sinus), proceed directly to surgical closure 1

2. Assess ASD size relative to patient weight: If ASD size-to-weight ratio >1.2, surgical approach is preferred 3

3. Evaluate septal rim adequacy: Deficient rims (absent or ≤4 mm) favor surgical approach 3, 5

4. Consider associated cardiac abnormalities: Presence of hypertrophic cardiomyopathy or other structural abnormalities favors surgical approach 2

Important Caveats

• Careful preoperative assessment with echocardiography is essential to characterize the defect type, size, and associated abnormalities

• Postoperative monitoring for complications such as postpericardiotomy syndrome is important 1

• Long-term follow-up is necessary to monitor for pulmonary hypertension, arrhythmias, or ventricular dysfunction 1