External carotid-to-middle cerebral bypass in the treatment of complex internal carotid injury.

Patients with penetrating carotid injuries above C2 present special challenges to the cerebrovascular surgeon. A subgroup of patients may lack the vascular collaterals necessary to tolerate carotid sacrifice or prolonged ischemia during direct carotid repair. We present a technique of extracranial-intracranial (EC-IC) saphenous vein bypass in two patients with high cervical and skull base carotid injuries and poor vascular collaterals. This technique allows preservation of internal carotid flow during the proximal anastomosis. Interruption of cerebral blood flow is limited to the duration required for a distal intracranial anastomosis and is confined to the territory supplied by a single middle cerebral branch. The procedure eliminates systemic anticoagulation, includes trapping of the injured segment of the internal carotid artery, and restores a volume of flow similar to that of the internal carotid artery. It is a valuable adjunct in this specific population of patients with high carotid injuries who cannot tolerate even brief periods of temporary occlusion or in whom clinical urgency precludes an endovascular trial occlusion.