1998 Volume 26 Issue 5 Pages 326-332
Generally, neurological deficits due to the mass effect of giant aneurysm are more severe in the posterior than in the anterior circulation. Direct surgical attack on giant thrombosed vertebral aneurysm involves trapping, and aneurysmectomy is often difficult. We report three cases of surgically treated giant thrombosed vertebral aneurysm, who presented with signs of mass effect without subarachnoid hemorrhage. Two cases were managed with partial aneurysmectomy after trapping of the vertebral artery, and one case with trapping and aneurysmectomy. Surgical results were satisfactory in all cases.
Internal decompression by thrombectomy, aneurysmectomy and trapping of the vertebral artery are thought to be reasonable operations for these aneurysms. In particular, the transcondylar approach is very useful in all cases. We discuss the operative method and intraoperative management of these aneurysms.
When the aneurysm is embedded in the brain stem, only a partial aneurysmectomy should be performed. Otherwise the brain stem will be injured and serious complications will occur. To reduce permanent severe complications of this operation, we use the following procedure.
1) Pre-operative precise diagnosis by using MRI and 3D-CT is very useful to determine the relation between the aneurysm, parent artery and the location of thrombus.
2) Trans-condylar approach is necessary to widen the operative field and to confirm of the position of the contralateral and distal vertebral artery.
3) Intraoperative continuous monitoring of SEP is necessary to monitor the brain stem function during operation.
4) Miniture doppler probe and micro optic fiber are useful aids to surgery.
