International experience with the use of Cocoon septal occluder for closure of atrial septal defects

Background: The Cocoon septal occluder (CSO) is a new generation double disk occluder device for catheter closure of the secundum atrial septal defect (ASD). Initial clinical evaluations with the use of this device have shown quite satisfactory results but large follow-up studies are missing. In this international multicenter study, we present procedural and follow-up data from 4008 patients with secundum ASD who underwent catheter closure with the use of CSO. Methods: The study cohort consisted of 1853 pediatric and 2155 adult patients with secundum ASD treated with the CSO. Patients were enrolled retrospectively from 11 international centers and were followed for a mean period of 43 months (range 12–84 months), postprocedural. Clinical, electrocardiographic, echocardiographic, procedural, and follow-up data were collected from each collaborating hospital. Results: The CSO was permanently implanted in 3983 patients (99.4%). Echocardiographic evaluation at one month follow-up revealed complete closure in 99.6% of those patients who had a device implanted. Thrombus formation in one adult patient was the only major device related to procedural complication. During the follow-up period, no patient developed cardiac erosions, allergic reactions to nickel, or other major complications. Conclusions: Implantation of CSO provided satisfactory procedural and follow-up results with high success and no device-related cardiac erosions and nickel allergy. © 2021 Hellenic Society of Cardiology