Part II - Decompression sickness, migraine, arterial deoxygenation syndromes European position paper on the management of patients with patent foramen ovale.Part II - Decompression sickness, migraine, arterial. The following are key perspectives from the European position paper on the management of patients with patent foramen ovale (PFO). The presence of a patent foramen ovale (PFO) is implicated in the pathogenesis of a number of medical conditions; however, the subject remains co. In patients with cryptogenic stroke, one of the most frequently found abnormalities is patent foramen ovale (PFO). Recent randomized trials have confirmed the role of patent foramen ovale (PFO) closure in the secondary prevention of cryptogenic stroke.