Pre-operative, Intra-operative, and Post-operative Management for ASD Cardiac Surgery
For patients with ASD undergoing cardiac surgery, comprehensive pre-operative assessment must include pulse oximetry at rest and with exercise, detailed imaging with TEE or cross-sectional imaging (CMR/CCT) to define septal anatomy and pulmonary venous connections, hemodynamic assessment to confirm Qp:Qs ratio ≥1.5:1 with right heart enlargement, and exclusion of severe pulmonary hypertension (PA pressure >2/3 systemic or PVR >2/3 systemic) which is an absolute contraindication to closure 1.
Pre-operative Assessment Algorithm
Essential Hemodynamic Evaluation
- Pulse oximetry testing: Perform at rest AND with exercise to identify shunt direction and detect patients with increased pulmonary vascular resistance 1
- Critical finding: Resting O2 sat >90% but dropping to <90% with activity indicates possible shunt reversal
- This identifies patients who may have contraindications to closure
Imaging Requirements
The imaging strategy must be comprehensive and ASD-subtype specific:
Transthoracic echocardiography (TTE): Limited utility in adults due to poor visualization of superior/posterior atrial septum 1
Transesophageal echocardiography (TEE):
- Excellent for visualizing entire atrial septum and pulmonary venous connections 1
- Particularly valuable for superior sinus venosus defects with anomalous right upper/middle lobe pulmonary venous connections
- Both 2D and 3D TEE are effective, though 3D TEE provides superior measurements for complex defects 2
Cross-sectional imaging (CMR or CCT): Ideal for delineating all pulmonary venous connections, especially those not well-visualized by TEE 1
Hemodynamic Criteria for Surgical Closure
Proceed with closure when 1:
- Qp:Qs ≥1.5:1 with right atrial and RV enlargement
- No cyanosis at rest or exercise
- PA systolic pressure <2/3 systemic pressure
- PVR <2/3 systemic resistance
Absolute contraindications to closure 1:
- PA systolic pressure >2/3 systemic
- PVR >2/3 systemic
- Net right-to-left shunt present
Pre-operative Risk Stratification
Recent evidence identifies specific high-risk features 3:
- Prematurity (9.62-fold increased mortality risk)
- Oxygen saturation <90% (5.89-fold increased mortality risk)
- Age <1 year (2.24-fold increased infection risk)
- Low WHO weight/BMI for age <5th percentile (2.36-fold increased infection risk)
- Noncardiac anomalies (4.67-fold increased infection risk)
- Chromosomal abnormalities (2.54-fold increased infection risk)
Interventional Cardiology Review
Common pitfall: Approximately 31% of surgical ASD patients undergo interventional cardiology review first, with 40% deemed inappropriate for catheter-based closure 4. To avoid delays, establish clear institutional criteria for which patients should bypass interventional review and proceed directly to surgical evaluation—typically those with:
- Primum ASDs
- Sinus venosus defects
- Insufficient rims for device closure
- Very large defects (>38mm)
Intra-operative Management
Surgical Approach Selection
Multiple approaches are safe and effective 5:
- Partial lower sternotomy
- Right anterior small thoracotomy with transthoracic clamping
- Totally endoscopic approach (da Vinci system)
- All approaches show similar ventilation times, ICU stays, and hospital lengths of stay
Intra-operative TEE Verification
- Mandatory: Complete defect closure must be verified by intraoperative TEE in all patients 5
- For complex defects, 3D TEE provides more accurate rim measurements (IVC rim, aortic rim) and optimal device sizing compared to 2D TEE alone 2
Post-operative Management
Expected Outcomes
Modern surgical ASD repair demonstrates excellent safety 3, 6:
- In-hospital mortality: 0.45%
- Major infection rate: 0.65%
- Median ICU length of stay: 27 hours
Monitoring for Complications
- Residual shunting: Rare but requires surveillance; approximately 1-2% may need reoperation 5
- Arrhythmias: Monitor for atrial tachycardia, particularly in adult patients with long-standing defects 7
- Infection surveillance: Heightened vigilance in high-risk patients (young age, low weight, chromosomal abnormalities) 3
Follow-up Considerations
Long-term complications in ASD patients include 7:
- Atrial arrhythmias
- Thromboembolism risk
- Right heart failure
- Late pulmonary arterial hypertension (in subset of patients)
Critical caveat: These recommendations apply only to isolated ASDs. Patients with ASD associated with complex congenital heart disease (e.g., Ebstein anomaly with pulmonary stenosis) require individualized assessment, as ASD closure could cause clinical deterioration 1.