Endovascular “Boost”: External Carotid Angioplasty to Augment Flow Before Superficial Temporal−Middle Cerebral Artery Bypass

Background: Superficial temporal artery−middle cerebral artery (STA-MCA) bypass may be used to augment cerebral blood flow in patients with select cerebrovascular pathologies or after failed attempts at revascularization. In this article we describe the use of balloon angioplasty to boost the flow of the external carotid artery (ECA) including the STA to be later used as a donor artery for a STA-MCA bypass procedure. Case Description: A 67-year-old male with bilateral carotid artery stenosis presented 2 days after a right middle cerebral artery (MCA) stroke and was admitted for medical management. Over the next 4 days his examination worsened; magnetic resonance imaging and computed tomography perfusion confirmed a right MCA stroke with penumbra and angiography revealed complete occlusion of the right internal carotid artery within a prior carotid stent. There was also a right ECA stenosis at its origin, thus limiting options for traditional extracranial-intracranial bypass. Therefore the patient underwent balloon angioplasty of the right ECA by traversing the carotid stent followed by right STA-MCA bypass, resulting in increased flow, clinical stability, and improved cerebral perfusion. Conclusions: This case highlights a unique strategy for the management of internal carotid artery occlusion in combination with an ipsilateral ECA stenosis. We also demonstrate the utility of endovascular adjuncts to open vascular surgery when complex patterns of stenosis or occlusion exist.