Ruptured A3 segment aneurysm in a patient with neurofibromatosis type 1: a case report and literature review

Neurofibromatosis type 1 (NF1) is a genetic disorder occasionally complicated by vasculopathy, but the concurrence of NF1, a ruptured distal anterior cerebral artery (ACA) aneurysm, and moyamoya syndrome is exceedingly rare. Literature review revealed that fewer than 20 such cases have been reported in English publications to date. The management of such complex, multifocal cerebrovascular pathology-including the choice of therapy, the risk of procedural complications, and the need for lifelong surveillance-poses significant challenges.

A 44-year-old man with clinical features of NF1 presented with sudden headache, dizziness, and transient syncope. Imaging revealed a ruptured saccular aneurysm arising from the right A3 segment of the ACA, accompanied by intraventricular hemorrhage and contralateral moyamoya-like vasculopathy. Given the aneurysm's deep pericalosal location, small size, and the patient's multiple scalp neurofibromas, endovascular coil embolization was selected over microsurgical clipping. The procedure was successfully performed via a transfemoral approach, achieving complete aneurysm occlusion with preservation of the parent artery. The patient recovered well neurologically. Remarkably, digital subtraction angiography at more than five years post-embolization confirmed durable occlusion of the treated aneurysm without recurrence. However, it also demonstrated progression of the moyamoya syndrome and revealed a new, untreated aneurysm at the right ophthalmic segment.

This case illustrates that endovascular coil embolization can be a safe and effective first-line treatment for ruptured distal ACA aneurysms in the complex setting of NF1 vasculopathy, providing long-term protection from rebleeding. The long-term follow-up uniquely highlights that NF1-associated cerebrovascular disease is progressive and multifocal; successful treatment of an index ruptured aneurysm does not eliminate the risk of new lesions elsewhere. Therefore, indefinite vascular surveillance is warranted in these patients. This report underscores the importance of a tailored, multidisciplinary approach and lifelong monitoring in managing NF1-related cerebrovascular complications.