小脳動脈末梢性脳動脈瘤の検討

抄録

Peripheral cerebellar artery aneurysms are very rare lesions. The reported incidences of the superior cerebellar artery (SCA), anterior inferior cerebellar artery (AICA), and posterior inferior cerebellar artery (PICA) peripheral aneurysms are 0.07%, 0.3%, and 1.0%, respectively. We performed neck clipping of one SCA aneurysm, one AICA aneurysm, and five PICA aneurysms between 2009 and 2018. The three aneurysms were ruptured ones. The outcome was good, with minimal surgical complications in all seven patients. Three illustrative cases are presented in detail.

Case 1 was of a 77-year-old woman who presented with a subarachnoid hemorrhage due to rupture of a peripheral SCA aneurysm. Neck clipping of the aneurysm was successfully performed using the occipital interhemispheric transtentorial approach. Case 2 involved a 68-year-old woman with a partially thrombosed, unruptured aneurysm of the PICA. The aneurysm was found embedded in the floor of the fourth ventricle and was associated with perianeurysmal edema of the medulla oblongata. The aneurysm was exposed using trans-cerebello-medullary fissure approach, and neck clipping was successfully performed. Case 3 involved a 56-year-old man with a peripheral AICA aneurysm. The aneurysm was exposed between the abducens and the auditory nerves through the lateral suboccipital route. The aneurysm was occluded without damage to the cranial nerves or brainstem.

Case selection is important in performing microsurgery or intravascular surgery for peripheral cerebellar aneurysms. Neck clipping should be applied as far as possible to achieve complete aneurysm obstruction without sacrificing the parent artery.