[PS3-1C-2] Early evaluation using superficial temporal Artery duplex ultrasonography after bypass surgery for moyamoya Disease
Surgical treatment is usually recommended to reduce the incidence of ischemic brain damage for moyamoya disease. In addition, the results of the Japan Adult Moyamoya Trial suggest that direct bypasses prevent rebleeding. Indirect bypass can be performed with a lower incidence of complications than direct bypass. However, patients do exist who exhibit a poor response to the indirect method, and some require additive revascularization surgery. Therefore, it is necessary to evaluate the development of the collateral circulation as early as possible postoperatively. We describe the efficacy of superficial temporal artery duplex ultrasonography (STDU) after bypass surgery in adult moyamoya disease. Fifteen adult patients (>17 years old) with moyamoya disease (22 affected sides) who underwent encephalo-duro-arterio-synangiosis (EDAS) were included in this study. STDU was performed before and 3, 6, and 12 months postoperatively. Digital subtraction angiography was performed 1 year after the operation to evaluate the development of collateral circulation. In good responders, the pulsatility index obtained by STDU showed a drastic decrease 3 months after the operation, while it did not change significantly in poor responders. Absence of this decrease in the pulsatility index along with no change in the flow velocity reliably indicated poor responders. Neovascularization after EDAS can be evaluated noninvasively in early phase using STDU and this method may be useful not only adult but also pediatric patients.