Atrial Septal Defect (ASD) is a congenital heart defect where there is an abnormal opening in the wall (septum) that divides the upper chambers of the heart (the atria). This allows oxygen-rich blood from the left atrium to mix with oxygen-poor blood in the right atrium, potentially leading to increased blood flow to the lungs, heart enlargement, and other complications over time.


Indications for Closure:

  • Significant Shunt: When there is a large left-to-right shunt (Qp:Qs ratio greater than 1.5:1) causing right heart volume overload.

  • Symptoms: Such as shortness of breath, fatigue, palpitations, or cyanosis due to the defect.

  • Paradoxical Embolism: Presence or risk of stroke or transient ischemic attacks (TIA) due to blood clots potentially passing through the ASD.

  • Atrial Arrhythmias: Atrial fibrillation or flutter associated with the defect.

  • Pulmonary Hypertension: To prevent or treat the development or progression of pulmonary hypertension.

  • Heart Enlargement: Evidence of right heart enlargement on echocardiography.

  • Progression of Symptoms: Even in adults where the defect was previously small or asymptomatic, if symptoms develop or the heart function is compromised.


Techniques for Closure:

Surgical Closure:

  • Open Heart Surgery: Traditionally done via a median sternotomy, the defect is closed either by direct suturing or using a patch made from synthetic material or the patient's pericardium. This approach is necessary for complex ASDs like sinus venosus or ostium primum defects, where associated anomalies require surgical correction.


Transcatheter (Percutaneous) Closure:

  • Device Closure: This less invasive method involves inserting a closure device through a catheter, typically through the femoral vein. The device, which looks like two discs connected by a waist, is deployed so that one disc lies in the left atrium and the other in the right, sandwiching the defect. This technique is primarily used for secundum ASDs with adequate rims for stable device placement:

    • Indications: Suitable for secundum ASDs where there's enough septal tissue to anchor the device without impinging on surrounding structures.

    • Procedure: Under fluoroscopy and echocardiographic guidance, the device is maneuvered to the defect. Once in position, it's released to close the hole.

    • Devices: Common devices include the Amplatzer Septal Occluder and the Gore Helex Septal Occluder, among others.


Considerations:

  • Size and Location: The size of the defect and its location determine the approach. Large defects or those with deficient rims might not be suitable for device closure.

  • Age and Health: Younger patients with no significant comorbidities are often candidates for device closure, but older patients or those with additional heart issues might require surgical intervention.

  • Follow-Up: Post-procedure monitoring is crucial to ensure there is no residual shunt, device migration, or development of arrhythmias.


Both methods have evolved to reduce morbidity, with transcatheter closure becoming the preferred approach for eligible ASDs due to its less invasive nature, offering quicker recovery times and reduced hospital stays. However, the choice between surgical and percutaneous techniques depends on individual patient factors, including the anatomy of the defect, patient health, and surgeon experience.