Acute Basilar Artery Occlusion in a Patient With Left Subclavian Artery Occlusion Due to First Rib Anomaly

A previously healthy 22-year-old man presented with thoracic outlet syndrome manifesting as Raynaud's phenomenon in the left hand and embolic occlusion of the basilar artery. Three-dimensional computed tomography angiography showed that the left subclavian artery was occluded as it passed over the abnormal first rib. Retrograde propagation of the thrombus from the site of arterial occlusion and/or reflux of embolic material was suspected. Medical therapy was started. The patient underwent resection of the anomalous rib. Postoperative angiography demonstrated that the subclavian artery was recanalized with almost normal distal flow. The basilar artery was also recanalized. Thoracic outlet syndrome due to a first rib anomaly may cause stroke.