Professor Jong-Min Song’s Team at Asan Medical Center Analyzes 748 Cases of Percutaneous Closure Using a Catheter-Based Occlusion Device

“Accurate Measurement of the Shape and Size of Cardiac Defects Using 3D Imaging Before the Procedure Helps Reduce Errors and Procedure Time.”

▲ Professor Jong-Min Song of the Division of Cardiology at Asan Medical Center
 

Atrial septal defect is a congenital heart defect in which there is a hole in the wall between the right and left atria, allowing blood to leak into the right atrium. It is often treated with a procedure that inserts an occlusion device through a catheter to close the hole between the atria.

Selecting an occlusion device that precisely matches the size of the atrial opening is crucial for the procedure. However, there have been no standardized international guidelines for determining the appropriate size of the occlusion device.

A research team led by Professor Jong-Min Song of the Division of Cardiology at Asan Medical Center recently reported that using 3D echocardiography to precisely measure the size and shape of the atrial opening before performing percutaneous closure of atrial septal defect enabled accurate selection of the occlusion device, achieving a procedure success rate of 99.7 percent and significantly improving safety and efficiency.

As the largest study to demonstrate the outcomes of percutaneous closure of atrial septal defect using 3D echocardiography, the findings are expected to contribute to establishing guidelines for determining the appropriate size of occlusion devices.

Atrial septal defect often shows no symptoms and is frequently diagnosed during newborn screenings, or later in adulthood when symptoms begin to appear. Blood leaking from the atrial opening into the right atrium can cause fatigue and shortness of breath, and in severe cases may lead to serious complications such as heart failure, pulmonary hypertension, arrhythmia, or stroke, making treatment necessary.

In recent years, percutaneous closure has become the preferred treatment, in which a catheter is inserted through a leg vein to place an occlusion device that seals the hole between the atria, avoiding open-chest surgery.

Selecting the correct size of the occlusion device is crucial. If the device is too small, it may not stay in place and could dislodge. If it is too large, it may continuously irritate surrounding tissues and cause damage.

To determine the size of the occlusion device, the conventional method has been to insert a balloon into the atrial defect during the procedure, inflate it, and measure its diameter. This “balloon sizing” method can overstretch the atrial septum, potentially leading to selection of a device larger than necessary. In addition, prolonged measurement time can, in rare cases, cause complications such as cardiac injury.

Recently, 3D transesophageal echocardiography has been used, in which an ultrasound-equipped endoscope is inserted through the esophagus to provide three-dimensional imaging of the heart. This allows clear observation of the heart’s internal structures from multiple angles.

Professor Jong-Min Song’s team used 3D transesophageal echocardiography at Asan Medical Center from September 2016 to May 2024 to pre-determine the occlusion device size before percutaneous closure in 748 adult patients with atrial septal defect. The patients were followed for an average of 1.6 years after the procedure.

The study found a procedure success rate of 99.7 percent, with no cardiac-related deaths reported during the follow-up period.

Excluding two cases out of 748 in which the procedure failed due to device malfunction, only one case required resizing of the occlusion device during the procedure. Similarly, only one case was converted to open-heart surgery. By using 3D echocardiography to accurately measure the maximum and minimum diameters of the atrial opening before the procedure, the need for reoperation or procedural errors was greatly reduced.

In addition, pre-determining the device size using 3D echocardiography significantly shortened procedure time. The average procedure time was 18 minutes, more than half the time compared with the 45 to 66 minutes typically required using the conventional balloon sizing method.

Professor Jong-Min Song of the Division of Cardiology at Asan Medical Center stated, “Using 3D transesophageal echocardiography to accurately assess the size and shape of an atrial septal defect before the procedure can reduce the risk of complications associated with the balloon sizing process, while also decreasing procedure time and radiation exposure.”

He added, “Our study found that approximately 25 percent of atrial septal defects are oval-shaped, with the longest dimension varying greatly among patients. Conventional balloon sizing can underestimate the defect size by up to 35 percent. Considering this, determining the occlusion device size using 3D transesophageal echocardiography may be the most effective approach.”

The study was recently published in the prestigious international journal European Heart Journal – Cardiovascular Imaging (Impact Factor 6.6).

Meanwhile, Asan Medical Center treats one in five adult patients with atrial septal defect in Korea and continues to lead advances in cardiac care. The center actively applies 3D transesophageal echocardiography to determine occlusion device size in clinical practice, and uses 3D imaging to identify defects unsuitable for percutaneous closure in advance, avoiding unnecessary procedures and providing optimal treatment that improves patients’ quality of life.