Matricidal Giant Transitional-Type Cavernous Aneurysm in a Child Presenting with Ophthalmoplegia and Repetitive Transient Ischemic Hemispheric Symptoms Treated with Flow Diverter Stent: Parent Artery Reconstruction, Aneurysm Exclusion, and Complete Resolution of Ischemic and Ocular Symptoms

Intracranial aneurysms in children are rare and occur much less frequently than in adults, accounting for <5% of all aneurysms. Giant, dissecting, and fusiform aneurysms are over-represented in the pediatric population. Among them, cavernous carotid artery aneurysms (CCAAs) represent a unique subset of intracranial aneurysms due to their distinct natural history and cavernous sinus anatomy. Transitional aneurysms constitute a particular subgroup of cavernous aneurysms that arise entirely from within the cavernous sinus but project into the extracavernous intradural subarachnoid space. Like other intracranial aneurysms, they have increased risk of rupture. Growing CCAAs can cause displacement and compression of the parent internal carotid artery (ICA), leading to luminal stenosis. Aneurysms that cause luminal stenosis of the parent vessel have been called “matricidal” aneurysms. Though many patients are asymptomatic, presenting symptoms of CCAAs include ophthalmoplegia with resulting diplopia, vision changes, pain, ptosis, facial numbness, cavernous-carotid fistula, epistaxis, subarachnoid hemorrhage, and – in cases of matricidal aneurysms – ischemia due to parent artery stenosis. We present our experience with a 5-year-old girl with an unremarkable medical past, who presented with a 2-week history of progressive subacute left orbital discomfort turning to frank pain followed by rapidly progressing ophthalmoplegia causing diplopia and alterations in visual acuity. She was evaluated by two senior ophthalmologists who referred her for a neurological evaluation. However, 4 days later her orbital pain worsened, she developed diplopia and weakness in her right hand, and she experienced four episodes of dysarthric speech. She was admitted to the emergency room, and neuroradiological studies revealed a large left carotid artery aneurysm causing a cavernous sinus mass effect. The angiographic evaluation confirmed that the aneurysm caused parent artery displacement with critical luminal compression and stenosis of the left ICA. The circle of Willis was incomplete and she had limited primary collateral anatomy, and we anticipated a balloon occlusion test failure. Thus, despite some technical caveats relating to the distal landing zone caliber, vessel tortuosity, and questionable compliance of dual antiplatelets in a child, we performed a flow-diverter stent implant with repeated balloon angioplasty. The procedure achieved aneurysm exclusion, mass effect reduction, and preservation of the parent artery, with progressive clinical improvement leading to a complete recovery. This case illustrates the successful treatment of a matricidal aneurysm using a flow-diverter stent implant in cases that are not amenable to parent artery occlusion.