The aim of this study was to evaluate the safety and efficacy of the Cardi-O-Fix plug used for the treatment of muscular ventricular septal defects.

We retrospectively reviewed the medical records of five patients with muscular ventricular septal defects who underwent transcatheter closure using the Cardi-O-Fix Plug, from November 2017 to August 2019. The median age was 5.1 years (range: 3.2–6.5). Their median body weight was 18.1 kg (range: 13.4–21.8). All the patients underwent detailed two-dimensional Doppler and colour flow imaging by transthoracic echocardiography. The left ventricular median defect size of the muscular ventricular septal defects was 5.6 mm (range: 5.3–7.0). The right ventricular median defect size of the muscular ventricular septal defects was 3.9 mm (range: 3.3–4.7). All the procedures were performed on beating hearts.

All the patients underwent successful device implantation with no displacement or detachment, they have complete echocardiographic closure at the 1-year follow-up. There were no occluder-related arrhythmia, chordae tendineae rupture, tricuspid insufficiency, aortic regurgitation, haemolysis, or embolisation.

Application of the Cardi-O-Fix plug appears to be a feasible, safe, and effective treatment option for patients with muscular ventricular septal defects. Longer follow-up periods are warranted to prove the conclusion for long-term outcomes.