Development of Arteriovenous Fistula After Revascularization Bypass for Moyamoya Disease

BACKGROUND AND IMPORTANCE Moyamoya disease is a rare cerebrovascular disorder often treated by direct and indirect revascularization bypass techniques as a result of a typically devastating disease course and poor response to medical therapy. In this report, we describe the formation and subsequent management of a de novo arteriovenous fistula identified in the setting of a patient treated with direct bypass surgery, a previously unreported phenomenon. CLINICAL PRESENTATION A 51-year-old woman presenting with Suzuki stage IV bilateral moyamoya disease underwent bilateral extracranial-to-intracranial superficial temporal artery--to--middle cerebral artery bypass without complication at our institution. At the 6-month follow-up, she demonstrated no evidence of residual neurological deficits or continued symptoms despite documentation of an arteriovenous fistula arising at the site of the right extracranial-to-intracranial bypass on routine follow-up cerebral angiography. CONCLUSION We present the first reported case of de novo arteriovenous fistula formation after superficial temporal artery-to-middle cerebral artery bypass for the treatment of moyamoya disease. Treatment of such iatrogenic arteriovenous fistulae fed by a patent bypass vessel may prove challenging without associated compromise of the bypass, meriting careful evaluation of all potential therapeutic options. The fistula described herein most likely occurred secondary to recanalization of a previously thrombosed vein of Trolard. This case demonstrates the possibility of arteriovenous fistula formation as a potential sequela of revascularization bypass surgery and lends support to the previously described traumatic origin of fistula formation.