Transcatheter closure of perimembranous ventricular septal defects using Amplatzer asymmetric ventricular septal defect occluder: Preliminary experience with 18-month follow up

Background: This study reports our experience in the nonsurgical closure of perimembranous ventricular septal defects in children and adolescents with the Amplatzer asymmetric ventricular septal defect occluder and the outcome of an 18-month follow up. Methods and Results: Twenty patients (median age:10 years; median weight:32 kg) with perimembranous ventricular septal defect were selected for transcatheter closure with the Amplatzer device. The prosthesis diameter chosen was 1-2 mm larger than the largest measured diameter of the defect on transesophageal echo (TEE). All patients were put on oral aspirin (5 mg/kg/day in children and 150 mg/day in adults) five days prior to and for six months after closure. Follow-up evaluation at 48 hr and 1, 6,12 and 18 months included clinical examination, electrocardiogram, and a transthoracic echocardiogram. The mean defect diameter on color flow mapping on TEE was 7.1 +/- 2.3 mm. The device diameter ranged from 6-14 mm (median = 8 mm). One patient developed an anaphylactic reaction to contrast. The procedure was successful in 17 out of 19 patients where it was attempted (89.4%). In two patients with associated significant aortic valve prolapse and mild aortic regurgitation the device could not be successfully deployed. A trivial residual shunt observed during postdeployment left ventricular angiogram in 7 of 17 patients (41.2%) completely disappeared at one month follow-up. Three patients had right bundle branch block (2 complete and 1 incomplete) whereas one developed junctional escape rhythm with a right bundle branch block morphology. One patient had clinically silent thromboembolism to the left vertebral artery and another patient had hemolysis which resolved spontaneously within 48 hr. Follow-up at 13.5 +/- 5.3 months (range 1-18 months) revealed no residual shunt. The left ventricular internal dimension in diastole decreased significantly from 45 6 mm to 40 6 mm (P < 0.01) at the time of the last follow up. The baseline tricuspid regurgitation (n = 4) and aortic regurgitation (n = 3) remained unchanged during the follow up period. None of the patients developed left ventricular outflow tract obstruction or new aortic or tricuspid regurgitation. There were no other device related complications such as device migration, systemic thromboembolism, infective endocarditis, pericardial effusion or delayed conduction disturbances. Conclusions: In carefully selected children and young adults, the Amplatzer asymmetric ventricular septal defect occluder is a promising device for transcatheter closure of perimembranous ventricular septal defect with encouraging results on short term follow up.