Can transcatheter occlusion of a persistent foramen ovale prevent paradoxical embolism?

Background and objective: Cerebral embolism may have different causes with sometimes serious consequences. If no specific reason can be found, paradoxical embolization through a persistent foramen ovate (PFO) is increasingly as a cause of the cerebral ischaemia. This study was undertaken to ascertain whether in patients with cerebral embolism occlusion of a PFO with a transcatheter technique can prevent further cerebral emboli. Patients and methods: Indications for transcatheter occlusion were based on neurological signs (ischaemic stroke), cardiovascular diagnosis, and coagulation tests. Between August 1991 and July 1996, transcatheter occlusion of a PFO was performed in 28 fully anticoagulated patients (median age 37.8 [15.4-65.4] years). The mean PFO diameter was 9.5 mm (3-17), mean duration of fluoroscopy 18.3 (8.7-43.1) min. The Rashkind device was implanted in three patients, the Sideris buttoned device in 25. During the follow-up period (2-64 months; mean 13 months) renewed neurological symptoms occurred in only one patient. Transoesophageal echocardiography excluded thrombi on the implanted device or in the left atrium, and a residual PFO. The cause of the one neurological episode is therefore not clear. All other patients have remained free of symptoms and recurrence without anticoagulation after placement of the device. Conclusions: Transcatheter occlusion of a PFO is a relatively simple and safe procedure. Our results suggest that it can at least lower the incidence of further cerebral embolizations. The clinical value of the method in comparison with anticoagulation requires further study.