BACKGROUND: In the event of early failure of standard extracranial-intracranial arterial bypass, elective but prompt revision surgery is generally attempted under the assumption that early occlusion is permanent. However, little is known about the occurrence of spontaneous revascularization. OBJECTIVE: To estimate the frequency and time course of spontaneous recanalization in primary extracranial-intracranial arterial bypass occlusion and re-evaluate diagnostic and therapeutic options facing spontaneous development. METHODS AND RESULTS: In a retrospective analysis 176 patients with standard superficial temporal artery/middle cerebral artery bypass were included. Twenty-three patients had primary bypass occlusion. In 7 cases spontaneous recanalization was observed. Follow-up of these cases is presented. CONCLUSIONS: Early bypass occlusion has a high incidence of spontaneous recanalization within the first year. In stable patients the first choice may be noninvasive follow-up and postponing revision operation.
