De Novo Distal Middle Cerebral Artery Aneurysm Post-excision of Intracerebral Arteriovenous Malformation in an 8-year Old

Cerebral arteriovenous malformations (AVMs) are frequently associated with concurrent aneurysms. These aneurysms are commonly haemodynamically related to the AVM and can be classified into extranidal or intranidal in reference to the AVM nidus. An aneurysm arising from an artery that does not angiographically contribute to the blood flow to the AVM is uncommon. A distal middle cerebral artery (dMCA) aneurysm itself is also a rare presentation, especially in paediatric population. We present a rare case of dMCA aneurysm that was noted after successful surgical management of a ruptured AVM in an 8-year-old child and its management. BACKGROUND: About 10-30% of patients with cerebral arteriovenous malformation (AVM) have an associated artery aneurysm. The majority of these aneurysms are flow-related to the malformation. These aneurysms can be classified into extranidal or intranidal in reference to the AVM nidus Rammos et al Am J Neuroradiol 37:1966-1971, [1]. An aneurysm arising from a different artery that does not angiographically contribute to the blood flow associated with the AVM is less common and would generally be regarded as unrelated to the AVM. Distal cerebral artery aneurysm itself is also a rare presentation, comprising of 1-7% of all middle cerebral artery aneurysm. In children, mycotic infection and dissection are the two most common causes for aneurysm in this location. Unlike in adults, berry aneurysms are uncommon in children. We describe a young patient who was found to have distal middle cerebral artery (dMCA) aneurysm in follow-up DSA (Digital Subtraction Angiogram) after the initial successful surgical treatment for a cerebral frontal AVM. In this particular case, endovascular repair is thought to be the best strategy to treat the aneurysm. However, there still remains a lack of consensus of the best management strategy (surgery or endovascular) in treating flow-related aneurysms in general. This is usually based on an individual case scenario and the treatment is tailored depending on various factors including the expertise of the treating team.