No abstract

In the last years, a shift from the microsurgical treatment to an endovascular therapy in patients with basilar apex aneurysm has been settled, part of this phenomenon is related to the significant tendency of vital perforators to be involved in the aneurysm dissection and clipping, which can implicate unfavorable outcomes. Nevertheless, microsurgical treatment remains the treatment that can provide the superior rates of stable and durable aneurysm occlusion, which is most important to young patients.In this video, we present the case of a 45-yr-old female patient who complained of a sudden and severe headache and presented with progressive lethargy during the following 3 d.At admission, computed tomography did not show abnormal findings. However, cerebrospinal fluid analysis showed erythrocytes and corroborated the clinical suspicion of spontaneous subarachnoid hemorrhage. The patient signed the Institutional Consent Form, which allows the use of his/her images and videos for any type of medical publications in conferences and/or scientific articles.Angiography and magnetic resonance imaging revealed a saccular basilar apex aneurysm. It showed a wide neck as well as a lobulated dome with upward and slightly left projection. The aneurysm did not involve angiographically visible thalamoperforator arteries, which allowed the microsurgical treatment by the fronto-orbitozygomatic approach. However, during the interpeduncular cistern dissection, an intraoperative rupture of the aneurysm occurred. This video exemplifies the steps required to manage an intraoperative rupture of a basilar apex aneurysm.

The distal posterior inferior cerebellar artery (PICA) is a rare site of aneurysm formation. Only small case series and case reports regarding surgical treatment are found in the literature.The PICA is divided into 5 segments (anterior medullary, lateral medullary, tonsilomedullary, telovelotonsillary, and cortical), and the distal ones represent the most complex, due to anatomic variations. We present a case of a 69-yr-old female patient who has suffered from a sudden and intense occipital headache, associated with nausea and vomiting. CT scan showed intraventricular hemorrhage, and further investigation with MRI and MR Angiography revealed a small distal PICA aneurysm, at the superior part of the medial aspect of the left cerebellar tonsil. Digital angiography has demonstrated the aneurysm at the tonsilomedullary segment of the PICA. In this 3-dimensional video, the authors show the microsurgical clipping of a saccular distal PICA aneurysm in the close relation to a choroidal branch, performed by median suboccipital craniotomy. Step-by-step of the dissection, relevant surrounding anatomy and aneurysm clipping is demonstrated. The patient signed the Institutional Consent Form, which allows the use of his/her images and videos for any type of medical publications in conferences and/or scientific articles.

Knowledge of the average distances between the neural structures in the cerebellar-pontine fissure and the angular relationships between these structures facilitates the use of surgical approaches such as microsurgery and endoscopy.