[Patent foramen ovale: conservative or surgical therapy?]

Notwithstanding the difficulties in definitely confirming paradoxical embolism, the association between patent foramen ovale (PFO) and cryptogenic stroke has repeatedly been demonstrated in clinical studies. Moreover, the recurrence rate of cerebral ischemia in patients with PFO and an unexplained stroke was found to be 3-4% per year in two recently published series. With the exception of right atrial pressure elevation in the setting of major pulmonary embolism, a reliable risk stratification of patients with PFO based on clinical or echocardiographic findings is not yet possible. The presence of atrial septal aneurysm, a wide opening of the defect during the cardiac cycle and a large atrial shunt have been implicated as risk factors by some investigators. Long-term prevention of paradoxical embolism with oral anticoagulants seems to be of questionable benefit. Besides, these agents are poorly tolerated and carry the risk of significant or fatal bleeding at a rate of 2-5% per year. Surgery of the atrial septum has been performed for many decades in patients with atrial septal defect and evidence accumulates that it is a safe and highly effective procedure in patients with PFO. At present, surgical closure of the PFO appears to be the treatment of choice for secondary prevention of paradoxical embolism. However, further studies are needed to define the appropriate candidates for surgical treatment. Devices for catheter-based sealing of PFO are also available and are currently being evaluated in clinical trials. However, experience with their use remains confined to specialized centers. Furthermore, further technical improvements of these systems are needed in order to optimize successful delivery and positioning, increase their long-term stability, and reduce periprocedural complications.