The temporopolar approach to the basilar apex aneurysm has the advantage of offering a wide working space for clipping but has the disadvantage of sacificing a draining vein from the superficial sylvian vein to the sphenoparietal sinus. We analyze methods that have been employed in our institution to provide a wide working space.
The techniques are divided into 3 categories based on the depth of surgical procedure: A, superficial layer; B, middle layer; and C, deep layer. Techniques in the superficial layer are zygomatic (n=9) or orbitozygomatic (n=3) osteotomy. Techniques in the middle layers include sectioning or dissection of the anterior temporal artery (n=5), retraction of the temporal lobe (n=18), and a combined approach (n=2). Techniques in the deep layer are optic unroofing (n=7), removal of the anterior (n=4) or posterior clinoid process (n=8), separation of tentorium (n=8), direct retraction in the posterior circulation (n=16), and sectioning of the posterior communicating artery (n=9). These techniques were used in 58 of 107 cases of basilar apex aneurysms.
When the temporal bridging veins developed well, the extended pterional approach or combined approach is effective to secure a wide working space. The extended pterional approach enables retraction of the temporal lobe without sacrificing the venous system. In the combined approach, the pterional and subtemporal approaches are undertaken through the same craniotomy. These methods were employed in 5 cases with successful clipping avoiding brain damage related to the occlusion of the venous system. These techniques were found to be beneficial to preserve the temporal bridging vein and also to provide a wide working space and access from various directions when approaching a basilar apex aneurysm.
