Ruptured Basilar Artery Blood Blister-Like Aneurysm Treated Using a Single Low-Profile Visualized Intraluminal Support (LVIS) Stent: A Case Report.

A basilar artery blood blister-like aneurysm (BBA) is a rare entity for which a standard treatment has not yet been established. We report a case of basilar artery BBA in the subacute stage of subarachnoid hemorrhage (SAH) that was treated using a single low-profile visualized intraluminal support (LVIS) stent. A 63-year-old woman presented with sudden-onset posterior neck pain. Head computed tomography (CT) revealed modified Fisher group 3 SAH, extending from the prepontine and basal cisterns to the quadrigeminal cistern. The patient was diagnosed with Hunt and Hess grade 2 SAH. Initial digital subtraction angiography (DSA) revealed an aneurysm in the right internal carotid artery (ICA), which was treated with coil embolization. Although a minute bulge on the basilar artery was identified on the initial three-dimensional DSA (3D DSA), it was too subtle for a definitive diagnosis on day 1. Repeat DSA was performed on day 11 because hemorrhage from the posterior circulation could not be excluded. DSA on day 11 revealed a 1.7-mm projection on the dorsal wall of the basilar artery by 3D DSA, confirming a basilar artery BBA. Dual antiplatelet therapy (DAPT) was initiated, and endovascular treatment was performed. The BBA was extremely small with a pinhole neck, making stent-assisted coil embolization difficult and high-risk for rupture; therefore, a single LVIS stent was placed in the basilar artery, forming a dense stent mesh around the aneurysm. The postoperative course was uneventful, and the patient was discharged without neurological deficit. Four months later, follow-up DSA showed complete resolution of the BBA. If coil placement is challenging in basilar artery BBA, treatment with a single LVIS stent may be an effective alternative option.