Transcatheter Closure of Congenital Muscular Ventricular Septal Defect

The success with occlusion devices for the closure of atrial septal defects and patent ductus arteriosus prompted the transcatheter closure of single and multiple muscular ventricular septal defects (VSD). The procedure for VSD was first attempted by Lock et al. in 1988 and devices originally designed for the closure of other intracardiac defects (Rashkind umbrella device, Lock clamshell, Cardioseal, coils, Sideris buttoned device etc.) were used with a variable success rate and a residual shunt. Recently, specially designed Amplatzer muscular VSD occluder and Sideris device are in use. The Amplatzer muscular VSD occluder has been undergoing clinical trial since 1998 after the animal experiments had shown 100% occlusion and complete endothelization at 3 months. The procedure was first attempted in August 1995 using the Rashkind umbrella device and since April 1998 only the Amplatzer muscular VSD occluder has been used. Of the149 patients who underwent transcatheter closure of VSD, 50 had muscular trabecular defects in various locations: mid-muscular, anterior, posterior, or apical. All cases were selected by detailed transthoracic and/or transesophageal echocardiography (TTE) and aneurysm of the muscular septum was observed in three of them. The age range was 3-28 years and the diameter of VSD was 4-11 mm. In all but one patient, the device was deployed from the venous side. Simultaneous TTE was done for proper positioning of the device and continuous electrocardiographic monitoring was also done for any arrhythmia/conduction defects. All patients were followed up every 3 months and received 3-5 mg/kg aspirin for 6 months. The procedure was successful in all patients. The Rashkind umbrella device (17 mm) was used in two and Amplatzer muscular VSD occluder (6-14 mm) in 48 patients. Forty-four devices were delivered by antegrade transvenous approach and six by the transjugular route. None had residual shunt, new aortic regurgitation, or tricuspid regurgitation. Transient complete heart block after 24 hours was noticed in one patient. On a follow-up of 2-90 months, the device was in position in all patients. There was no embolization of the device, and no late-conduction defects, infective endocarditis, or hemolysis. Transcatheter closure of muscular VSD is safe and efficacious, and should be considered as a procedure of choice as an alternative to surgery that avoids cardiopulmonary bypass.