Abstract WP414: Ultrasonographic Changes after Indirect Bypass Surgery in Pediatric Patients with Moyamoya Disease

Abstract

Background: The marked cerebral hypoperfusion caused by moyamoya disease (MMD) usually manifests as ischemic stroke or transient ischemic attack. The treatment of choice for MMD is extracranial-intracranial bypass surgery; however, the changes of ultrasonographic features following indirect bypass surgery are unknown. This study sought to characterize the ultrasonographic changes that result from indirect bypass surgery in pediatric patients with MMD. Methods: We prospectively recruited 15 pediatric MMD patients who had undergone a total of 19 indirect bypass surgeries (encephaloduroarteriosynangiosis, EDAS) and obtained the relevant clinical and radiological characteristics. Neurovascular ultrasonography of extracranial and intracranial arteries was performed pre-operatively and post-operatively at 1, 3, and 6 months. Results: Among the 15 patients (11 males, 4 females), the mean age was 10.4 ± 4.6 years. Among the extracranial arteries, the superficial temporal artery presented the most pronounced increase in flow velocity and decrease in flow resistance, beginning at 1 month post-op (all p<0.01). Among the large intracranial arteries, a significant increase in mean flow velocity was observed in the anterior cerebral artery since 3 months post-op (p<0.05). Conclusion: Significant hemodynamic changes were observed in pediatric MMD patients after EDAS surgery, as evidenced by periodic ultrasonographic assessment.