A ruptured aneurysm in the vasa corona at the craniocervical junction with dysgenesis of the posterior inferior cerebellar artery

Aneurysms Arising from Persistent Arteries in the Vertebrobasilar Paramedian Longitudinal Axis: Two Case Reports

A 50-year-old man and a 69-year-old woman with consciousness disturbance were diagnosed to have suffered from subarachnoid hemorrhage (SAH) involving the posterior fossa. In both cases, the initial 3D CT angiogram failed to reveal the SAH source in the vertebrobasilar system. Delayed 3D rotational angiography revealed aneurysms on unfamiliar aberrant arteries. One was a dissecting aneurysm located between the proximal part of the posterior inferior cerebellar artery and the distal part of the intracranial vertebral artery. It was trapped and resected; the patient subsequently presented with lateral medullary symptoms. The other aneurysm was between the distal posterior and the distal anterior inferior cerebellar artery. It was successfully embolized; there were no complications. We think that the aberrant aneurysm-harboring vessels encountered in these two patients were primitive arteries on or adjacent to the vertebrobasilar paramedian longitudinal axis and that they persisted past the embryologic stage. Such aneurysms arising from unfamiliar persistent arteries beside the brainstem are extremely rare but must be considered when the SAH source is not detected in the trunk of the vertebrobasilar system.

Ruptured aneurysm arising at anterior spinal artery as the collateral circulation with bulbar artery supply to posterior inferior cerebellar artery treated by proximal occlusion and occipital artery-posterior inferior cerebellar artery bypass: a case report and literature review

The cases of aneurysms arising from collateral vessels that supply the posterior inferior cerebellar artery (PICA) are so exceptionally rare that there is no consensus on the optimal treatment. In this report, a patient was presented with subarachnoid hemorrhage caused by a fusiform aneurysm on the right anterior spinal artery, which formed an anastomosis network with bulbar artery and the vessels supplying to the right PICA. We chose to perform proximal occlusion on the anterior spinal and bulbar arteries, using occipital artery-PICA bypass. Our case was the first where proximal occlusion was used concurrently with vascular reconstruction to treat a ruptured aneurysm of collateral vessels supplying to PICA.