Spontaneous Resolution of Dural and Pial Arteriovenous Fistulae Arising After Superficial Temporal Artery to Middle Cerebral Artery Bypass for Moyamoya Disease

BACKGROUND: Superficial temporal artery (STA)-to-middle cerebral artery bypass is frequently performed for moyamoya disease. We discuss an unusual case in a moyamoya patient complicated by the development of dural and pial arteriovenous fistulae (AVF). Both AVF then spontaneously resolved 2 years after surgery. CASE DESCRIPTION: A patient in the fifth decade of life presented after multiple strokes resulting in right-sided weakness and numbness. Magnetic resonance imaging revealed remote strokes, and angiography revealed Suzuki grade 3 moyamoya angiopathy bilaterally. With a diminutive left STA, we initially performed left-sided dual-vessel pial synangioses. After radiographic evidence of robust revascularization and improved hemispheric perfusion, a combined right STA-middle cerebral artery bypass was done. However, routine 8-month postoperative angiography identified dural and pial AVF within the prior operative field. On the 2-year surveillance cerebral angiogram, both AVF were no longer present. CONCLUSIONS: AVF as a complication of revascularization surgery is rare. Here, we discuss the possible pathophysiologic mechanisms that we theorize may have contributed and current treatment options and indications. We also review the literature surrounding this phenomenon.