Abstract
Although the pterional approach (PA) is the most commonly employed for the intracranial aneurysms in the anterior circulation and of the upper portion of the basilar artery (BA), there are some difficult cases among them in clipping surgery with PA. In the past 8 years, we used skull base approaches to access and treat 41 aneurysms involving the anterior communicating artery complex, middle cerebral artery, proximal internal carotid artery (ICA) or BA. The approaches included orbital osteotomy and orbitozygomatic osteotomy. Removal of the rim and roof of the orbit and additional decompression of the optic nerve and anterior clinoid resection, namely, the orbitocranial approach (OCA) allowed shorter and multi-directional accesses to the highly-located aneurysms with a minimal brain retraction.
OCA was very useful for clipping surgeries of a high BA aneurysm and of a ruptured aneurysm in the anterior circulation with a swollen brain in the acute stage. Orbitozygomatic temporopolar approach, which consists of the frontotemporal and orbitozygomatic osteotomy, allowed more upward visual axis through the temporopolar route and multidirectional working space for a high BA tip aneurysm associated with a short intracranial ICA. Skull base surgeries, used selectively, can provide improved access to highly-located aneurysms and large or giant aneurysms, while minimizing brain retraction.
