External carotid artery stenting in symptomatic internal carotid artery occlusion

We report the case of a patient with an anterior ischemic stroke due to tandem occlusion of the left M2 segment and ipsilateral internal carotid artery (ICA), with concomitant severe stenosis of the ipsilateral external carotid artery (ECA) and contralateral ICA, and moderate stenosis of the left vertebral artery (VA); as thrombectomy was not possible, stenting of the right ICA was performed. Two days after significant recovery, the patient showed neurological deterioration when in upright position, and brain magnetic resonance imaging confirmed decreased cerebral blood flow on the left hemisphere. Stenting of the left ECA and balloon angioplasty of the ipsilateral VA were performed in order to increase collateral flow, with an almost complete resolution of symptoms. This case highlights the importance of assessing the collateralization pattern when an ICA occlusion is present, and the potential need to revascularize an ipsilateral stenotic ECA.