Stent-Assisted Coiling for a Ruptured Wide-Neck Basilar Artery Trunk Aneurysm With Preservation of Brainstem Perforators: A Case Report

Basilar artery trunk aneurysms are rare, accounting for 2.1% of all intracranial aneurysms. Among these, Mizutani type 4 (nonbranching true aneurysms) carries a particularly high risk of rupture and rebleeding. Although endovascular therapy is common, reports on the safety and efficacy of stent-assisted coiling (SAC) for ruptured wide-neck basilar artery trunk aneurysms in the acute phase remain limited. A 60-year-old man presented with subarachnoid hemorrhage (World Federation of Neurosurgical Societies grade I). Imaging revealed a wide-neck saccular aneurysm (4.8 mm dome diameter, 5.4 mm neck width) in the basilar artery trunk, consistent with a Mizutani type 4 aneurysm. On day 2, SAC was performed using a Neuroform Atlas stent. Because the patient required no additional invasive procedures like external ventricular drainage, dual antiplatelet therapy (DAPT) was initiated immediately before the procedure. Complete occlusion was achieved while maintaining the patency of the brainstem perforators. The patient was discharged with a modified Rankin Scale score of 0, and stable occlusion was maintained at the three-month follow-up. In conclusion, SAC using the Neuroform Atlas stent on DAPT is a viable treatment option for ruptured wide-neck basilar artery trunk aneurysms. This approach allows for secure aneurysm occlusion while minimizing the risk of ischemic complications in the perforator-rich basilar trunk.