What is the treatment for an atrial septum aneurysm?

Treatment of Atrial Septum Aneurysm

The treatment of atrial septum aneurysm (ASA) should be based on associated conditions and risk factors, with antiplatelet therapy recommended for isolated ASA and device closure considered when ASA is associated with patent foramen ovale (PFO) or atrial septal defect (ASD), especially in patients with history of cryptogenic stroke.

Diagnostic Evaluation

When an atrial septal aneurysm is identified, a thorough evaluation should include:

• Transesophageal echocardiography (TEE) to:

  • Assess aneurysm morphology and mobility
  • Detect associated defects (PFO, ASD)
  • Identify potential thrombi within the aneurysm
  • Evaluate for interatrial shunting

• Assessment for associated conditions:

  • History of cryptogenic stroke or TIA
  • Presence of mitral valve prolapse
  • Evidence of right ventricular volume overload

Treatment Algorithm

1. Isolated ASA (without PFO/ASD)

• Asymptomatic patients without history of embolic events:

  • Clinical monitoring without specific therapy
  • Consider antiplatelet therapy if ASA membrane thickness ≥5mm 1

• Patients with history of cryptogenic stroke/TIA:

  • Antiplatelet therapy (aspirin) or anticoagulation 2
  • Decision should be based on risk factors and membrane characteristics
  • ASA with thickened membrane (≥5mm) has higher association with cerebrovascular events 1

2. ASA with Patent Foramen Ovale

• Patients with cryptogenic stroke:

  • PFO closure with device is recommended 3
  • Device closure is feasible and effective in patients with ASA 4, 5

• Patients without history of stroke:

  • Antiplatelet therapy may be considered
  • Device closure may be considered in high-risk patients (large shunt, associated ASA)

3. ASA with Atrial Septal Defect

• ASD >5mm with evidence of right ventricular volume overload:

  • Closure is recommended (surgical or device) 3, 6
  • Surgical closure is preferred for:
    • Sinus venosus, coronary sinus, and primum defects
    • Complex ASA with multiple fenestrations
    • Large defects with inadequate rims

• Device closure is appropriate for:

  • Secundum ASDs with suitable anatomy
  • ASA with single or limited fenestrations 4, 5

Device Selection and Procedural Considerations

For patients undergoing device closure:

• Amplatzer septal occluders have shown good results in patients with ASA 5
• Multiple devices may be required for ASA with multiple fenestrations 5
• Pre-procedural TEE is essential to characterize the anatomy 3
• Post-procedure follow-up should include:
  • Echocardiographic assessment at 24 hours, 1 month, 6 months, and 1 year 3
  • Monitoring for device-related complications (migration, erosion, thrombus)

Follow-up Recommendations

• Annual clinical follow-up for patients after ASD/PFO closure 3
• Monitoring for:
  • Pulmonary arterial hypertension
  • Atrial arrhythmias
  • Right or left ventricular dysfunction
  • Device-related complications

Important Considerations and Pitfalls

• ASA is not merely an incidental finding but may be associated with increased risk of thromboembolic events 7, 2

• The mechanism of embolization may include:

  • Thrombus formation within the aneurysm itself
  • Paradoxical embolization through associated interatrial communications
  • Association with mitral valve prolapse 2

• Careful evaluation for other potential cardiac sources of embolism is essential before attributing stroke to ASA

• Device closure in patients with ASA appears to have similar success rates compared to those without ASA 4

By following this structured approach, clinicians can effectively manage patients with atrial septal aneurysm based on associated conditions and risk factors, with the primary goal of preventing thromboembolic complications.