2025 Volume 53 Issue 5 Pages 312-318
We report a case in which an arteriovenous fistula (AVF) persisted despite confirmed obliteration of the nidus following Gamma Knife treatment for a frontal lobe arteriovenous malformation (AVM) and led to progressive enlargement of a venous aneurysm over time, necessitating embolization via endovascular treatment.
A 9-year-old girl presented with headaches. Magnetic resonance imaging (MRI) revealed a left frontal lobe AVM with a maximum diameter of 4 cm, classified as Spetzler-Martin grade 3. Cerebral angiography revealed multiple feeders from the bilateral anterior cerebral arteries supplying the nidus with three distinct draining veins. Gamma Knife treatment was performed, and the disappearance of the nidus was confirmed. However, the AVF remained, and progressively enlarged varices were observed. AVF embolization was performed using a combination of coils and Onyx. The shunt flow was successfully eliminated postoperatively, and the patient was discharged home without any new neurological deficits.
A fistulous component may be present in AVMs with high-flow shunts. In this case, Gamma Knife treatment might have selectively obliterated only the nidus, leading to the manifestation of AVF. However, there is no consensus on the natural course or optimal treatment strategies for such cases. In this patient, rapid enlargement of the venous aneurysm was observed over a short period, and early intervention was performed considering the risk of hemorrhage. In rare cases, individualized treatment planning and meticulous long-term follow-up with detailed imaging assessments are required.
