Transcatheter closure of atrial septal defect in symptomatic children weighing ≤10 kg: Addressing unanswered issues from a decade of experience

Background and Objectives : Device closure of secundum atrial septal defect is shown to be feasible and effective in children weighing <= 10 kg. Issues such as how large is too large, how to choose device size, does the length of the interatrial septum (IAS) matter, and need for technical modifications for successful device delivery have not been systematically addressed. Materials and Methods : This is a retrospective study, comprising 45 patients weighing <= 10 kg, who were chosen for device closure between January 2010 and June 2018. Patient selection was done on basis of transthoracic echocardiography. Device closure was done using Amplatzer septal occluder. The device size was selected primarily based on transesophageal echocardiography (TEE)-measured defect diameter. Although IAS length was taken into consideration, adequate rim size was the key factor in deciding device closure of the defect. Results : Forty-three out of 45 patients had successful device closure. The mean age and weight were 25.71 +/- 8.62 months and 8.99 +/- 1.24 kg, respectively. The defect measuring as large as 27 mm (14.89 +/- 3.89) on TEE was closed and device as big as 28 mm was successfully deployed (16.7 +/- 4.31). Regular technique of device deployment was successful in only 15 cases. In the remaining 28, one of the modified techniques was used. There was no mortality, failure of the procedure, device embolization, thromboembolism, or pericardial effusion. One patient developed moderate mitral regurgitation and two patients had transient atrioventricular block. At follow-up, all patients showed significant improvement in symptoms and growth without any complications. Conclusions : Defect size as large as three times the weight in kg can be closed in small children. Devices as large as 28 mm can be deployed in these hearts provided the surrounding rims are adequate. In majority of cases, one of the modified techniques is essential for successful deployment. IAS length is not a limiting factor for deciding the size of the device used.