Pre-procedural Transesophageal Echocardiography Underestimates Atrial Septal Defect Size Compared to the Balloon Sizing Technique

Background: Secundum-type atrial septal defects (ASD) are increasingly being treated with percutaneous placement of occluding devices. Accurate sizing of the ASD is mandatory for subsequent optimal selection of the device. We sought to compare the two most commonly used methods, 2 – dimensional transesophageal echocardiography (2D-TEE) and stretched- balloon sizing . Methods: Sixteen patients (8 men and 8 women) aged 53.8±9.8 years with ASD were scheduled for implantation of an Amplatzer septal occluder device. The procedure was performed with the use of local only anesthesia via the right femoral vein with fluoroscopic guidance alone and without the intra-procedural use of 2D-TEE. The size of the defect was measured with 2D-TEE prior to the procedure. In the catheterization laboratory the ASD size was measured again with the insertion of a sizing ballon inflated with diluted contrast agent until a waist appeared. Waist dimensions were measured using cineangiographic  quantitation (QCA) software. Results: All ASDs were successfully closed with Amplatzer occluders. A significant correlation was found between echocardiographic and fluoroscopic measurements of the ASD size (r=0.863, p=0.000). However, most of the echocardiographic measurements underestimated ASD diameters compared with conventional QCA balloon sizing by a mean of 3 mm (16.46±5.93 mm vs 19.83 ±6.3 mm, t= 4.18, p= 0.001). Conclusions: Atrial septal defects can be treated safely and effectively with the percutaneous placement of an Amplatzer septal occluder device via a simple percutaneous technique with use of local anesthesia and fluoroscopy alone without a need for intra-procedural 2D-TEE. Although the use of pre-procedural 2D-TEE has been a common practice for establishing the diagnosis and offering an initial assessment of the size of the defect, it largely underestimates the latter. The single-plane fluoroscopic balloon sizing performed during the procedure seems indispensable for choosing an occluding device of appropriate size. &nbsp