Patent foramen ovale (PFO) has been identified as a potential source of paradoxical embolism. Frequent forms of presentation of paradoxical embolism include cryptogenic stroke， peripheral embolism and decompression sickness in underwater divers. Transcatheter closure of PFO is a promising alternative to surgical closure or anticoagulation therapy to prevent paradoxical embolic events in patients with PFO. Several different devices have been used for transcatheter PFO closure. Dr Horst Sievert， Frankfurt， Germany， presented the results of the EU Study during Friday afternoons First Report Investigations session.
　　The Spider PFO occluder (Lifetech Scientific (Shenzhen， China)) is a self-expandable， double disc device and is composed of a right disc of a ceramic coated Nitinol wire mesh and a left disc of an ePTFE membrane with four or six ceramic coated braided Nitinol anchors. The joint between the left and right discs allows them free rotation so the occluder can adapt to morphology. This will be the first device made in China to receive the CE mark.
　　The EU Study enlisted 50 patients (18F， 32M) from March to December 2010 aged 21 to 76 years (mean 52 years) all with a prior neurological event (stroke or TIA). Procedures were performed under local anesthetic and followed up at one and six months with ECG， TEE and TCD. There were no procedural or technical complications experienced and implantation was successful in all cases. At one month follow up， there were no major adverse events but three short periods of atrial fibrillation had been experienced. TCD showed complete closure in 27 of the 50 patients and TEE showed all devices in position， no thrombus and complete closure in 34/50. At six months there were no new adverse events. TCD results were complete closure in 16 of 29 examined and TEE also showed all devices in position， no thrombus and complete closure of 18 of the 29 represented patients.
　　The conclusions drawn from this study indicated that the ceramic nitinol may cause less thrombus formation and lead to faster endothelialization and improve bicompatability. Overall， initial results from this and the first-in-human trial of this device conducted by Dr Zhang et al (China)， show that the device is safe. Further follow-up data is required to evaluate closure rates.