Follow-up Study to Monitor the Efficacy and Safety of the Occlutech® mVSD Cases

Inclusion Criteria * A participant will be eligible for study participation if he/she meets the indication and area of application as laid down in the IFU. The Occlutech mVSD is indicated for percutaneous occlusion of hemodynamically or clinically significant muscular ventricular septal defects. * Any age * Male or female. * Patients understand the nature of the study and provide their informed consent to participation. * Patients willing and able to attend the follow-up visits and procedures foreseen by study CIP. Contraindication * Hemodynamically relevant VSD shunt * Congestive heart insufficiency * Recurrent respiratory infections * Failure to thrive. * Significant left ventricle (LV) enlargement * Significant left atrium (LA) enlargement * Other clinical indication Exclusion Criteria The device is contraindicated for participants known to have any of the following: ⦁Active bacterial infections * Active infection at the time of implantation * Allergy to antiplatelet or anticoagulant therapy * Allergy to nickel and/or titanium and/or nickel/titanium-based materials * Any type of serious infection 1 month before the procedure * The aortic rim of less than 2 mm * Demonstrated intracardiac thrombi on echocardiography * Malignancy where life expectancy is less than 3 years * mVSD diameter \> 20 mm * Perimembranous VSD Post-MI VSD * Recent myocardial infarction or a surgical bypass operation in the last 30 days * Sepsis (local or generalized) * Septal thickness \> 7 mm in the area of the Occluder placement