Fronto-temporo-orbitozygomatic craniotomy and "half-and-half" approach for basilar apex aneurysms

Basilar apex aneurysms (BAA) are located in interpeduncular cistern surrounded by eloquent neurovascular structures. Surgical access is difficult due to narrow surgical corridors and requires traversing through a depth of 6-8 cm of subarachnoid space.

Surgical management of BAAs clipped using frontotemporal craniotomy, orbitozygomatic osteotomy with combined subtemporal and transylvian (half and half) approach is discussed.

Tertiary care referral institute; prospective study.

Five patients with BAA rupture causing subarachnoid hemorrhage presented in modified Hunt and Hess (Hand H) grades II (n=1), III (n=1) and IV (n=3), respectively. In 4 patients, the aneurysms were 0.8-1.2 cm in diameter, situated 7 mm-1 cm above dorsum sellae. Two of them had posteriorly projecting aneurysms. One patient had a giant, high BAA with a left parietooccipital arteriovenous malformation. Vasospasm of posterior cerebral/proximal basilar artery was seen in 2 patients. In one patient, internal carotid artery was mobilized by intradural anterior clinoid drilling with carotid collar division. Triple-H therapy was administered following surgery.

There was no intraoperative rupture or temporary clipping. Follow up angiography showed complete aneurysmal obliteration with preservation of posterior cerebral and superior cerebellar arteries. Follow up (mean: 8.7+/-3.5 months) H and H grades were II (n=2) and III (n=3), respectively. The morbidity include caudate and thalamic region infarct, transient III rd nerve palsy and cerebrospinal fluid otorrhoea (n=1, respectively).

This simple approach provides a wide surgical corridor from 5 mm below to greater than 1 cm above dorsum sellae with adequate proximal control of basilar artery. It is an option to endovascular embolization especially with large and giant, or wide-necked BAA, vertebrobasilar tortuosity, coil compaction or postcoiling re-rupture and an associated large haematoma.