Patent foramen ovale: anatomical complexity and long-tunnel morphology related issues.

Patent foramen ovale (PFO) is present in about one-quarter of the population and should be considered an anatomical variant rather than a malformation. The association of PFO with cryptogenic stroke, migraine, peripheral embolism and other pathologies is still controversial. The evaluation of anatomical complexity, and particularly the long-tunnel morphology, is crucial for the assessment of the risk profile and for a targeted therapeutic...