Treatment and clinical course of Moyamoya disease with a coexisting internal carotid artery aneurysm in a pediatric patient

This report presents a management approach for a pediatric patient with Moyamoya disease complicated by coexisting cerebral aneurysms. A 9-year-old child presented with right-sided hemiparesis, facial weakness, delayed speech, and impaired motor function. Clinical evaluation revealed a four-year history of Moyamoya disease. MRI demonstrated significant bilateral narrowing of the internal carotid arteries, occlusion of the right anterior cerebral artery, and subocclusion of the anterior and middle cerebral arteries bilaterally. The patient subsequently underwent staged revascularization, including direct and indirect bypass surgeries on both hemispheres at six-month intervals. One year after the revascularization surgeries, the patient developed a seizure-like episode with loss of consciousness and was urgently readmitted to the hospital. Imaging identified a subarachnoid haemorrhage secondary to a de novo bifurcation aneurysm of the left carotid artery, for which emergency endovascular treatment was performed, resulting in successful aneurysm embolization. One year later, recurrence due to aneurysm recanalization within the left internal carotid artery required repeat embolization. Follow-up MRI performed one year after the second intervention demonstrated no evidence of aneurysm recanalization. This case underscores the necessity of a comprehensive, multidisciplinary approach to managing ruptured aneurysms in pediatric patients with Moyamoya disease. The integration of combined revascularization strategies with minimally invasive endovascular interventions proved critical in addressing both ischemic and hemorrhagic risks. Personalized treatment planning, tailored to the specific angiographic features, disease progression, and clinical profile of the patient, is essential for optimizing outcomes while minimizing procedural and long-term complications.