Background: Endovascular procedures and direct surgical clipping are the main therapeutic modalities for managing of BAAs. Furthermore, giant or wide-necked aneurysms and those that involve the PCA or perforators at its neck usually are not embolized.
Case description: A 55-year-old man presented to the emergency room complaining of sudden and intense headache. Neurological examination evidenced meningismus. Computed tomography disclosed a subarachnoid hemorrhage (Fisher grade III). Arteriograms revealed BAA, whose neck was partially obscured by the PCP. A standard pterional craniotomy was performed, followed by extensive drilling of the greater sphenoid wing. The neck was partially hidden by the PCP, and no proximal control was obtained without drilling the PCP and opening the CS (modified TcA). Drilling of the PCP was begun by cutting the overlying dura and extended caudally as much as possible. Next, opening of the roof of the CS was performed by incising the dura in the oculomotor trigone medial and parallel to the oculomotor nerve and lateral to ICA; the incision progressed posteriorly toward the dorsum sellae. Further resection of the dorsum sellae and clivus was carried out. After performing these steps, proximal control was obtained, aneurysm was deflated, perforators were saved, and aneurysm was clipped.
Conclusions: This study has demonstrated the clinical usefulness of an abbreviated form of the TcA, which led the "modified TcA," in approaching complex low-lying BAA. It provides additional surgical room by removing the PCP and partially opening the CS, which permits further bone removal and improves exposure.