Patients and methods:
We retrospectively reviewed thirty-eight patients who underwent a transcatheter closure of atrial septal defect from November 2018 to December 2019. In this study 28 patients were done at The Royal Brompton Hospital in London and 10 patients were done at The Children Hospital, Mansoura University, Egypt. There was no patients with significant residual shunts. However, we excluded two patients one of them had a major complication (device dislodgement) and the other one had multiple defects. A total of 36 patients composed study group.
All our patients had a percutaneous ASD closure under 3D TOE guidance as the presence of haemodynamically significant ASD and suitable anatomic characters. The device selection was done according to balloon sizing using the flow stopping technique.
We considered a procedure to be successful in all patients with no residual shunt or with residual shunt of less than 2 mm and without encroachment on the surrounding structures or other major complications (device dislodgement) Subsequently, we assumed that the device size was appropriate among those patients.
Echocardiographic assessment was conducted in all patients, using an IE 33 Philips machine and TEE probe X7-2t.
From transthoracic echocardiogram both color and 2D images of ASD were obtained in the standard subcostal view and the modified apical four chamber view, maximal dimensions of the ASD were measured.
During the transesophageal Echocardiography the ASD diameters were assessed using the standard views including a mid-oesophageal four-chamber view (0), a short-axis view (35 – 60) and a long-axis view (90 – 130). Continuous rotation was performed to track the maximal diameter and both colour and 2D pictures were obtained.
The 3D images were obtained in the mid-oesophageal bicaval view at around 90 degrees, the 3D zoom mode was activated and the zoom box was optimized in the lateral plane to include the opening of the SVC and IVC. The whole septum was included by optimizing the depth settings. A full volume for the IAS was obtained and then rotated anticlockwise for 90 degrees and turn the image leftwards, the SVC opening is directed upwards. This was considered anatomically oriented en face view of ASD from the RA perspective. Gain optimization was done to remove all blood shadows and optimise the image for accurate identification of defect border then the image was acquired.
An offline MPR was performed moving each axis to obtain an image, which included the whole ASD. Measurements of the minimal and maximal diameters were performed using two axes on the 2D images obtained by MPR (figure 1)
The maximal diameters were all compared with the device size. Three types of devices were encountered in this study which were Occulotech, Hyperion and Amplatzer according to the availability of the selected size.