Percutaneous patent foramen ovale occlusion: current evidence and evolving clinical practice

Patent foramen ovale (PFO) has long been implicated with cryptogenic stroke, migraine and decompression illness. PFO is common and its implicated pathologies cause devastating neurological sequelae; and hence have drawn the attention of medical practitioners across disciplines. The pathogenesis is hypothesized to be caused by micro-emboli or neuro-hormones which would otherwise being filtered by the lungs, astraying into the systemic circulation via the atrial communication especially during Valsalva maneuver. Treatment options have been proposed; among others are medical therapy, PFO closure or both. While medical therapy as secondary prevention is being adopted by most centers in the world, PFO closure is performed in selected patients only. The reason being is that most studies linking PFO to these pathologies are observational in nature. And these associations do not equate to a firm cause and effect relationship. For causal relationship to be established, good quality prospective data is required. Recently, there has been emergence of new prospective trials which improve the understanding of PFO closure in these pathologies. This article reviews the associations between PFO and the three main implicated pathologies as well as the evidence for PFO closure in the current era.