Subarachnoid hemorrhage from vertebral artery dissecting aneurysms involving the origin of the posteroinferior cerebellar artery: Report of two cases and review of the literature

OBJECTIVE AND IMPORTANCE: Few reports have been published on ruptured vertebral artery dissecting aneurysms in which the posteroinferior cerebellar artery (PICA) arises from the aneurysm wall, and there is ongoing debate as to the proper management of this type of aneurysm. This article describes two patients. CLINICAL PRESENTATION: Both patients presented with subarachnoid hemorrhage and were admitted to our institution on the day of rupture. Computed tomography revealed that the subarachnoid hemorrhage was located mainly in the posterior fossa. Cerebral angiography demonstrated a vertebral dissecting aneurysm involving the origin of the PICA. In one patient, the PICA was very large. INTERVENTION: One patient was treated by trapping, with the PICA involved in the trapped segment. Postoperatively, the patient experienced transient mild hoarseness and dysphasia but recovered completely, The other patient, whose PICA was very large, was initially treated by endovascular proximal occlusion. This resulted in marked enlargement of the distal part of the aneurysm, indicating a need for surgical treatment. A clip was applied to the origin of the PICA after anastomosis of the occipital artery to the PICA. The patient recovered well and was discharged with no neurological deficits. CONCLUSION: The ideal method of treatment for patients with dissecting aneurysms of the vertebral artery involving the PICA origin is complete isolation of the aneurysm by trapping, with revascularization of the PICA, However, trapping alone is one possible treatment option. If proximal clipping alone is carried out, follow-up angiography is mandatory to observe any changes in the aneurysm.