Percutaneous retrograde left external carotid artery coil embolization for management of hemorrhage from a persistent proatlantal intersegmental artery type 2

Type 2 left proatlantal artery with normal left vertebral artery and association with an aberrant right subclavian artery and a bi-carotid trunk

Type 2 proatlantal artery (PA) is a rare type of the carotid-vertebrobasilar anastomosis that arises from the external carotid artery and enters the posterior fossa via the foramen magnum (FM). The type 2 PA is usually large and takes a similar course to the occipital artery (OA). The peripheral branch of the OA arises from the distal segment, just proximal to the FM. The ipsilateral vertebral artery (VA) is usually aplastic or hypo-plastic. We diagnosed a case of relatively small type 2 left PA in a patient with a normally developed ipsilateral VA. Furthermore, the patient had an aberrant right subclavian artery associated with a bi-carotid trunk. The combination of these extracranial arterial variations has not been reported in the relevant English language literature.