Percutaneous closure of perimembranous ventricular septal defects: initial experience in Portugal

Closure of ventricular septal defects (VSDs) with significant shunt is indicated due to the risks associated with increased pulmonary flow leading to left chamber dilatation, the possibility of cardiac dysfunction and arrhythmias, and the risk of bacterial endocarditis. Percutaneous VSD closure is an effective and safe alternative to surgery in selected patients. However, perimembranous VSD (PMVSD) constitutes a special case since the technique for percutaneous closure is more complex and hence warrants individual evaluation.

To assess the efficacy and safety of percutaneous closure of PMVSD based on the initial experience of our center, the first to use this technique in Portugal.

Five patients, aged between 5 and 23 years, with PMVSD of a suitable size for percutaneous closure, were selected since they showed evidence of a significant left-to-right shunt together with left chamber dilatation. The procedure was performed under general anesthesia, guided by fluoroscopy and transesophageal echocardiography (TEE). A femoro-femoral arteriovenous loop was established and an Amplatzer occluder implanted, the characteristics and dimensions of which were chosen according to the angiographic and TEE findings. Besides therapeutic efficacy and complications during the procedure and follow-up, left ventricular dimensions and function and degree of mitral, aortic and tricuspid regurgitation were also assessed pre- and post-procedure, during a follow-up of 5 to 23 months.

All patients had a Qp:Qs ratio of > 2:1. In one case, the procedure was abandoned as the VSD diameter was over 17 mm, and the patient was referred for surgical closure. In the other four patients, two membranous (8 and 16 mm) and two muscular (6 and 12 mm) VSD occluders were used. On final angiographic assessment, no residual shunt was observed in any patient. One patient presented a transient junctional rhythm during the procedure. During follow-up, there was no prolongation of the PQ interval or de novo aortic regurgitation in any patient. Catheterization time ranged between 90 and 176 minutes and fluoroscopy time between 10 and 17 minutes.

1) Percutaneous closure of PMVSD is an effective and safe method of treatment in selected patients. 2) It is a complex procedure, but is likely to be refined and extended to a larger number of patients in suitably qualified centers.