Successful Internal Trapping of Vertebral Artery Dissecting Aneurysm Located between Double Origin of the Posterior Inferior Cerebellar Artery, Resulting in Antegrade Blood Flow: A Case Report.

Objective: The double origin of the posterior inferior cerebellar artery (DOPICA) is a rare variant of PICA. Vertebral artery dissecting aneurysm (VADA) with DOPICA is an extremely rare occurrence. Herein, we report a case of VADA located between DOPICA that was successfully treated with endovascular internal trapping.

Case presentation: A 48-year-old male, found collapsed at his workplace, was admitted to our hospital for emergency medical assistance. Head CT revealed a subarachnoid hemorrhage (Fisher group 3), and cerebral angiography revealed right VADA with DOPICA. The VADA was located distal to the proximal component of the posterior inferior cerebellar artery (PCPICA) and just proximal to the hypoplastic distal component of PICA (DCPICA). Emergency endovascular internal trapping was performed using a total of 13 coils from the distal end of the VADA to just the distal of the branching point of PCPICA. VADA was not visualized, and antegrade flow through DOPICA to the basilar artery was confirmed. Head magnetic resonance angiography (MRA) showed antegrade flow via DOPICA, and the patient was discharged home on Day 46 with a modified Rankin Scale 0.

Conclusion: Endovascular internal trapping for VADA with DOPICA was considered useful, especially when VADA is distal to PCPICA and proximal to DCPICA.