A rare aneurysm at a posterior communicating artery fenestration treated with the nautilus neck-bridging device: A case report.

Fenestrations of the posterior communicating artery (PCom) are rare vascular variants, and their association with aneurysm formation is uncommon. This report describes a ruptured aneurysm from a PCom fenestration, successfully managed with the Nautilus intrasaccular neck-bridging device. The patient presented with subarachnoid hemorrhage, and 3D-angiography showed a wide-necked aneurysm at the origin of a fenestrated PCom. Endovascular embolization using the Nautilus device and coil placement led to complete aneurysm occlusion while preserving the parent vessel. The patient recovered without neurological deficits, and a 12-month angiographic follow-up confirmed stable occlusion. This case demonstrates the technical feasibility and safety of the Nautilus device in treating complex ruptured aneurysms associated with rare vascular variants, contributing to the limited literature on PCom fenestration aneurysms. KEY POINTS: Fenestrations of the posterior communicating artery (PCom) are extremely rare, with only a few cases described in the literature. Aneurysms arising from PCom fenestration are even more uncommon and represent a technical challenge for both surgical and endovascular treatment. We report a ruptured aneurysm at a PCom fenestration successfully treated with the Nautilus neck-bridging device. This case illustrates the feasibility of Nautilus in complex ruptured aneurysms and ads to the scarce literature on PCom fenestrations and their association with aneurysms.