Antegrade horizontal stenting for endovascular coiling of wide-neck aneurysms in the basilar tip: Two case reports.

Rationale: Endovascular coil embolization for wide-neck intracranial aneurysms is technically challenging and requires supporting devices. Intracranial stents are widely used as a buttress for compact coil filling and preventing coil protrusion into the parent artery. Horizontal stenting has been developed to maximize coil insertion and reduce the risk of thromboembolism. An anterograde route for horizontal stenting could be attempted for basilar tip aneurysms if the posterior communicating artery is not accessible. Here, we report 2 cases of antegrade horizontal stenting (AHS) for wide-neck aneurysm (WNA) in the basilar tip. This approach aims to maximize coil insertion and achieve complete aneurysm occlusion.

Patient Concerns: Both patients were admitted for the treatment of cerebral aneurysms, which were incidentally detected during routine health checkups.

Diagnoses: Both patients were diagnosed with WNAs at the basilar tip and hypoplastic communicating arteries.

Interventions: The patients underwent stent-assisted coil embolization for WNA in the basilar tip using the catheter jailing technique. After positioning a pre-jailed microcatheter within a basilar aneurysm, AHS was performed using the Neuroform Atlas stent, with the proximal part of the stent deployed across the neck of the basilar tip aneurysm. In both cases, the preselected microcatheter tip shifted either to the anterior or posterior side of the aneurysm immediately after AHS using the pushing technique. The coils inserted into the aneurysm did not reach the opposite side of the microcatheter placement, necessitating additional catheterization.

Outcomes: Complete occlusion was achieved by inserting additional coils through the repositioned microcatheter.

Lessons: Horizontal stenting via an antegrade route may be an effective strategy for achieving compact coil embolization in selected patients with WNAs at the basilar tip. The Neuroform Atlas stent appears to be a promising tool for AHS owing to its hybrid-cell design. However, the shifting phenomenon of a jailed microcatheter after AHS warrants attention, as it may present potential challenges that require further catheterization.