Abstract
Based on an angiographic analysis, the author presents a selection of surgical approaches and important technical strategies for treating various basilar aneurysms. A lateral, non-subtracted angiogram was a key film for the selection of the surgical approach. In this angiographic analysis of basilar bifurcation aneurysms, several distinct characteristics were noted : the length and deviation of the ICA, the course of the PCA and the Pcom, the origin of the thalamo-perforators, and the location, direction, and width of the neck of each aneurysm. In patients with a short, laterally deviated ICA of the access side, a pterional approach for the resection of the anterior clinoid process, followed by detachment of the carotid ring, was found to be a useful procedure to enlarge the operational field. The proximity of PCA (Y-shaped PCA) or of the thalamo-perforating arteries to the aneurysm was seen to be a risk factor for clipping, especially for large aneurysms. For basilar trunk aneurysms, the use of the anterior transpetrosal approach was found to be advantageous, since retraction damage to the temporal lobe is reduced. Also, the surgical field was enlarged by opening Meckel's cave to mobilize the Vth nerve, as well as by resecting the petrous apex. This approach is indicated for aneurysms located between the pituitary base level and the internal auditory meatus, especially for aneurysms that project posteriorly.
