Intraoperative angiography for hunterian ligation of a recurrent basilar aneurysm

Cerebral aneurysms often recur after selective endovascular treatment with detachable coils and are usually treated by recoiling. Sometimes, however, surgical treatment is required, and application of the clip can be difficult. Evacuation of embolic material risks injuring eloquent structures or perforators, especially in the posterior circulation. In such cases parent vessel occlusion for reversal of flow might be an option. If collateral flow is adequate, an additional bypass is not required. When using this technique, known as Hunterian ligation, intraoperative monitoring such as electrophysiological monitoring and intraoperative angiography can be of great help and are advisable. We describe this procedure and related intraoperative considerations in one case report.