Effect of transcatheter closure by Amplatzer^TM Duct Occluder II in patients with small ventricular septal defect

Transcatheter closure of ventricular septal defect (VSD) is an alternative treatment of surgery. However, because of the potential risk of the complete atrioventricular block (AVB) and the lack of available dedicated devices for VSD, this procedure rarely used most centers. Recently in Thailand, with distinct device design that may cause less clamp force and radial force, the Amplatzer^TMDuct Occluder (ADO) II has become available for the closure of small VSDs. This is a retrospective review of 49 patients who underwent transcatheter VSD closure using ADO II at Songklanagarind hospital and Queen Sirikit National Institute of Child Health between January 2014 and December 2016 with an intention to report procedural success rate and 12-months-outcomes. Twenty-six cases were female. The median age and weight at treatment were 7.8 year (ranged from 1.9 to 25 year) and 25.1 kg (ranged from 11 and 57 kg). The majority (65.3%) of the VSD was a perimembranous defect. The mean diameter of LV entry was 5.2 ± 2.5 mm and the mean RV exit was 3.2 ± 0.8 mm. Four patients had more than 1 exit at RV orifice. The mean length of the VSD was 5.3 ± 1.8 mm. The mean aortic valve-VSD distance was 3.9 ± 2.0 mm. The mean tricuspid valve-VSD distance was 3.8 ± 2.5 mm. The procedural success achieved in all patients (100%), most of the implantations were performed in a retrograde approach (53.1%). The ADO II was successfully implanted in 2 cases (5%) who failed other devices in the first attempts. There were no major complications. There were no changes in the severity of tricuspid and aortic valve regurgitation immediate after implantation and at 12 months' follow-up. Three patients (6%) had tiny to small residual shunt at 12 months' follow-up. None of the patients had a complete heart block. However, new-onset of left bundle branch block and right bundle branch block occurred in 2 (5%) cases and 5 (10%) cases, respectively. With symmetrical double-disc design and softness of the device, the ADO II can be safely and effectively used for closure of the VSDs with the defect size less than 6 mm.