Rupture of a vertebral artery dissecting aneurysm developing immediately after trapping of a dissecting aneurysm on the contralateral vertebral artery: case report.

The development of vertebral artery (VA) dissecting aneurysm after trapping of the contralateral VA is rare, and rupture of angiographically occult VA dissecting aneurysms immediately after trapping is even less common. A 39-year-old man suffered subarachnoid hemorrhage caused by rupture of a left VA dissecting aneurysm. The VA was trapped and the left occipital artery anastomosed to the posterior inferior cerebellar artery. Postoperatively, he suddenly developed apnea and died of rupture of a right VA dissecting aneurysm. Histological examination of the bilateral VAs and the basilar artery disclosed a hematoma between the media and the adventitia. This case further confirms the need for careful preoperative imaging study of the dissection and all segments of the dissected vessel in patients requiring trapping of a VA dissecting aneurysm, as well as preservation of VA anterograde flow.