Traversing the vertebrobasilar junction to access the contralateral posterior inferior cerebellar artery (PICA) during complex posterior circulation aneurysm embolizations

The use of vertebrobasilar junction (VBJ) traversal provides an effective alternative for treating complex posterior circulation aneurysms when standard ipsilateral access is restricted, by enabling retrograde access to the posterior inferior cerebellar artery (PICA) branching from the targeted aneurysm. While experienced operators have employed this technique, a formal video-based demonstration of the approach is notably absent from the existing educational literature, underscoring the significance of this contribution as a resource for trainees and early-career neurointerventionists. We present two cases illustrating the utility of contralateral vertebral artery access via VBJ traversal. In the first case, a recurrent left PICA aneurysm was treated with stent-assisted coiling. In the second case, a ruptured left V4 dissecting aneurysm was managed with balloon-assisted coil sacrifice. In both cases, bilateral radial access facilitated a favorable microcatheter trajectory through the contralateral vertebral artery, enabling effective aneurysm treatment while preserving PICA patency. Bilateral radial access has been associated with reduced complication rates and improved procedural control in recent literature. Both patients had excellent clinical and angiographic outcomes, with no recurrence observed on follow-up imaging. Written informed consent was obtained from both patients for the procedures performed and for the inclusion of their anonymized clinical data and images in this report. These cases demonstrate the feasibility and potential benefits of VBJ traversal in treating posterior circulation aneurysms, particularly when conventional access strategies are technically challenging.