Transcatheter closure of patent foramen ovale using the Cocoon occluder: A multicenter retrospective study

The Cocoon patent foramen ovale (PFO) occluder is a new device especially designed for transcatheter closure of PFO. This occluder has some distinctive structural modifications aimed at reducing the risk of major complications of transcatheter PFO closure. In this report we present our initial experience to evaluate the efficacy and safety of the Cocoon PFO occluder in 253 patients who underwent transcatheter PFO closure.

The study cohort included 253 patients (median age 45 years) with embolic stroke of undetermined source who underwent attempted transcatheter closure of PFO for secondary prevention of paradoxical embolism. Patients were enrolled retrospectively from five sites in Greece and one in Romania between December 2016 and January 2021, and the median follow-up period was 28 months (range 12-48 months). Clinical and laboratory data from each participating center were sent to an electronic registry for evaluation and statistical analysis.

The Cocoon PFO occluder was permanently implanted in all patients. At 6 months, complete occlusion of PFO was observed in 251/253 (99.2%) patients. Three (1.2%) patients had a trivial residual shunt. Thrombus formation on the device, which was successfully treated with recombinant tissue plasminogen activator infusion, was observed in one (0.4%) patient. No other complications occurred. During a median follow-up period of 28 months, 3 (1.2%) patients, aged 64-67 years, developed new onset paroxysmal atrial fibrillation. No neurologic events, cardiac erosions, allergic reactions to nickel, or thrombus formation occurred.

The Cocoon PFO occluder is an effective and safe device that adds to our armamentarium for transcatheter closure of PFO.