Safety and efficacy of Amplatzer duct occluder II and konar-MF™ VSD occluder in the closure of perimembranous ventricular septal defects in children weighing less than 10 kg

Introduction: Device closure of perimembranous ventricular septal defects (pmVSD) is a successful off-label treatment alternative. We aim to report and compare the outcomes of pmVSD closure in children weighing less than 10 kg using Amplatzer Duct Occluder II (ADOII) and Konar-MF VSD Occluder (MFO) devices.Methods: Retrospective clinical data review of 52 children with hemodynamically significant pmVSD, and sent for transcatheter closure using ADOII and MFO, between January 2018 and January 2023. Baseline, procedural, and follow-up data were compared according to the implanted device.Results: ADOII devices were implanted in 22 children with a median age of 11 months (IQR, 4.1-14.7) and weight of 7.4 kg (IQR, 2.7-9.7). MFO devices were implanted in 30 children with a median age of 11 months (IQR, 4.8-16.6) and weight of 8 kg (IQR, 4.1-9.6). ADOII were implanted (retrograde, 68.1%) in defects with a median left ventricular diameter of 4.6 mm (IQR, 3.8-5.7) and right ventricular diameter of 3.5 mm (IQR, 3.1-4.9) while MFO were implanted (antegrade, 63.3%) in defects with a median left ventricular diameter of 7 mm (IQR, 5.2-11.3) (p > 0.05) and right ventricular diameter of 5 mm (IQR, 2.0, 3.5-6.2) (p < 0.05). The procedural and fluoroscopy times were shorter with the MFO device (p < 0.05). On a median follow-up of 41.2 months (IQR, 19.7-49.3), valvular insufficiency was not observed. One 13-month-old child (6.3 kg) with ADOII developed a complete atrioventricular heart block (CAVB) six months postoperative and required pacemaker implantation. One 11-month-old child (5.9 kg) with MFO developed a CAVB 3 days postoperative and the device was removed. At 6 months post-procedure, only one child with MFO still experiences a minor residual shunt. There was one arterio-venous fistula that resolved spontaneously.Conclusion: Both the MFO and ADOII are effective closure devices in appropriately selected pmVSDs. CAVB can occur with both devices. The MFO is inherently advantageous for defects larger than 6 mm and subaortic rims smaller than 3 mm. In the literature, our series represents the first study comparing the mid-term outcomes of MFO and ADOII devices in children weighing less than 10 kg.