Posterior Inferior Cerebellar Artery Aneurysm: Microsurgical Clipping of a Ruptured Posterior Inferior Cerebellar Artery (PICA) Aneurysm Not Well Suited to Endovascular Treatment, Far-Lateral Transcondylar Approach to the Anterior Medullary Segment of the PICA, Complete Exclusion of the Aneurysm with Preservation of the Parent Artery

Abstract

A 43-year-old female patient suffered a spontaneous subarachnoid hemorrhage (SAH), Hunt and Hess grade IV, Fisher grade 4, due to a ruptured left-sided posterior inferior cerebellar artery (PICA) aneurysm, arising from the anterior medullary segment of the PICA. The aneurysm had a wide neck, and the parent vessel was shown to supply part of the left anterior inferior cerebellar artery (AICA) territory. For these reasons, endovascular treatment was considered hazardous with respect to PICA preservation, and the patient underwent microsurgical clipping via a far-lateral transcondylar surgical approach. Clipping of the aneurysm was achieved without compromising the left PICA. The patient was discharged to a rehabilitation facility with a Glasgow Outcome Score of 4 (due to sequelae of the SAH). This case demonstrates that a well-tailored surgical approach to the PICA can yield good outcomes both clinically and radiologically. The microsurgical management of ruptured PICA aneurysms is the main topic of this chapter.