Catheter closure of atrial septal defects using the Cocoon septal occluder: preliminary results of a European multicenter study.

Despite its simplicity, device closure of atrial septal defects is still associated with rare but potentially lethal complications. In this prospective non-randomized multicenter study we investigated the safety and efficacy of the Cocoon septal occluder (CSO) for closure of atrial septal defects (ASDs) in 92 patients. Median age of the patients was 10.5 years (range 3-61 years) and median weight was 25 kg (range 13-65 kg). The device is an improved new generation double disc design made of Nitinol wire mesh that is coated with platinum using NanoFusion technology. The discs are connected by a waist with diameter ranging from 6mm to 40 mm with 2mm increments. All patients completed a 3-month follow-up. Mean ASD diameter was 21 ± 7 mm (range 10-35 mm), while the mean device diameter was 24 ± 8 mm (range 14-40 mm). The CSO was permanently implanted in all 92 patients. Complete echocardiographic closure of the defect immediately after the procedure or at the one month follow-up, was observed in all 92 patients (100%). No device-related complications were observed during the procedure or at short-term follow-up (range 3-12 months). Our preliminary results indicate that CSO is a promising device for transcatheter closure of ASDs. Further studies are required to document its efficacy, safety and long-term results in a larger patient population.