Management of Proximal Anterior Cerebral Artery Aneurysms: Anatomical Variations and Technical Nuances

OBJECTIVE: The proximal segment of the anterior cerebral artery (A1) is among the most uncommon locations for occurrence of an intracranial aneurysm. These aneurysms may be missed if small or misinterpreted when they are near the internal cerebral artery bifurcation or Anterior Communicating Artery region. The association with congenital vascular anomalies and multiplicity makes them unique. METHODS: Seventeen A1 aneurysms were diagnosed in sixteen patients between January 2000 and October 2014 in our institution. A retrospective review of the clinical, radiological, and management (microsurgical and endovascular) details of these patients was conducted. RESULTS: The incidence of A1 aneurysm was 1.71% of all patients harboring aneurysms and 1.19% of all aneurysms. Half of these patients exhibited subarachnoid hemorrhage. Fourteen aneurysms underwent microsurgical or endovascular intervention. All patients recovered well, except for one patient who died in the postoperative period. CONCLUSIONS: A1 aneurysms are rare, with wide anatomic variations. In this article, we discuss those variations in detail with illustrative cases and pictures. We also discussed the microsurgical and endovascular strategies to encounter them highlighting the technical challenges.