Routine use of 3-dimensional zoom modality with 2-dimensional transesophageal echocardiography to decide the candidacy for transcatheter device closure of atrial septal defect
Authors: Bhardwaj A , Pillai A , Satheesh S , Anantharaj A 
Published: October 2022

Abstract

Background
2-dimensional transesophageal echocardiography (2D-TEE) and balloon sizing are commonly used for assessment of Ostium secundum atrial septal defect (OS-ASD) prior to device closure but complications do occur. Therefore, assessment of accurate morphology and anatomy of the defect in three-dimensional plane is essential for transcatheter device closure to be successful, which the 2D TEE fails to reveal.

Purpose
2D TEE has long been used to decide size of the device required for transcatheter closure of OS-ASD and the appropriate candidates. However, complications like inadequate closure, leaving behind residual defect or device embolization often come into picture. The reason behind this is complex anatomy of some defects in the three-dimensional plane. Purpose of this study was to see if the routine use of 3D zoom with 2D TEE can better help to select the appropriate patients for device closure than that by 2 TEE alone.

Methods
We enrolled 71 OS-ASD patients from October 2020 to December 2021. All the patients underwent transesophageal echocardiography (TEE). Assessment of quantitative (number, shape and size of defect and size of residual rims) and qualitative (aneurysm, malalignment, fenestration) parameters was done by both 2D and 3D zoom. The measurements by 2D and 3D TEE clips were done by different operators. Transcatheter device closure was done for the patients with defect morphology and residual rims amenable for the same, with acceptable pulmonary pressure. Patients found to be adequate for the device closure by 2D TEE, when further found to have an unfavorable morphology by 3D TEE, were referred for surgical management. Follow up transthoracic echo was done after 1 month.

Results
Of the 71 patients, 65% were females and mean age was 26.23±10.75 years. By 3D TEE, 66% had circular defect,19% had oval defect and 14% had complex defect. 2 patients had spiral defect. Malalignment of the septum was seen in 4 (5.6%) patients by 2D TEE whereas in 13 (18.3%) patients by 3D TEE. Septal aneurysm was seen in 1 (1.4%) by 2D TEE whereas in 3 (4.2%) patients by 3D TEE. Mean largest size obtained by 2D was 24.82±9 mm and that by 3D was 26.23±8.42. By 3D TEE, 37 patients had at least one rim deficient (&lt;5 mm). 3D Maximal diameter strongly correlated with 2D Maximal diameter (correlation coefficient 0.860; p&lt;0.01). 9 (12.6%) patients found adequate for the device closure by 2D TEE were further found to have an unfavorable morphology by 3D TEE. 38 (53.5%) patients underwent device closure and 20 (28.2%) patients underwent surgical patch closure. At 1 month follow up all the 38 patients had device in-situ and had no residual shunt.

Conclusions
In OS-ASD patients, routine use of 3D zoom modality can complement 2D TEE in deciding appropriate patients for transcatheter device closure and help prevent many unforeseeable complications.

Funding Acknowledgement
Type of funding sources: Public Institution(s). Main funding source(s): Jawaharlal Institute of Postgraduate Medical Education and Research