Popliteal venous aneurysm with paradoxical embolization in a patient with patent foramen ovale.

An 18-year-old woman was found in bed with right-sided hemiplegia and global aphasia. Acute ischemic lesions in the left basal ganglia, the left insula cortex, and the cortex of the left parietal lobe were found on diffusion-weighted MRI (Figure 1). The patient underwent contrast echography, and a patent foramen ovale with right-to-left shunt was diagnosed (Figure 2). Systemic anticoagulation with heparin was initiated, and a regression of neurological signs and symptoms was observed. Comorbid diseases such as a coagulation disorder, a thrombus within a cardiac chamber, and cerebral or carotid atherosclerosis were excluded. A duplex scan revealed a 3.534 cm saccular popliteal venous aneurysm (Figure 3), which was confirmed by MRI and was presumed to be the origin of paradoxical embolization. The patient underwent tangential aneurysmectomy and lateral venorrhaphy of a 433.532.5 cm saccular venous aneurysm. No thrombus was noted within the aneurysm. In a second session, transcatheter closure of the foramen ovale with an umbrella system was performed. The patient tolerated both procedures well and has remained symptom-free.