2606470 EC-IC extracranial-intracranial 341 2606472 EC-IC external carotid-internal carotid 9 2606471 EC-IC extracranial-intracranial arterial 2 2606467 EC-IC extracranial-intracranial bypass 2 2606469 EC-IC carotid-external carotid 1 2606468 EC-IC emergent high-capacity extra- to intracranial 1 2606466 EC-IC Extracranial-intracranial bypass grafting 1 2606473 EC-IC post-extracranial to intracranial 1