Posterior cerebral aneurysm associated with complete occlusion of the middle cerebral artery caused subarachnoid hemorrhage: a case report
Kawamura, A.; Yamada, H.; Nagao, T.; Tamaki, N.
No Shinkei Geka. Neurological Surgery 24(12): 1107-1111
1996
ISSN/ISBN: 0301-2603 PMID: 8974093 Document Number: 457190
The authors reported a rare case of subarachnoid hemorrhage (SAH) from a left posterior cerebral artery (PCA) aneurysm at P2 portion associated with complete occlusion of the ipsilateral middle cerebral artery (MCA). A 65-year-old female suddenly complained of severe headache and was admitted with disturbance of consciousness. Apart from her somnolent condition, she showed no significant neurologic deficits such as aphasia or right hemiparesis. CT scan revealed the finding of SAH dominant in the left sylvian fissure and basal cistern. A small low density area which was considered as an old infarction was also recognized in the left putamen. Angiogram showed a left P2 portion aneurysm associated with complete occlusion of the ipsilateral MCA at its origin. Bilateral PCA was mainly supplied via posterior communicating artery (PCo) from anterior circulation. The clipping of the aneurysm was performed via a subtemporal approach 5 hours after the attack with special attention and care to prevent secondary brain damage due to the ischemic state caused by MCA occlusion. Transient neurological complication such as aphasia and right hemiparesis appeared postoperatively for a few days but recovered almost completely in a week after the ventriculoperitoneal shunt. Indication, timing and technique of operation and management after the operation must be well-discussed for cases of subarachnoid hemorrhage due to an aneurysm associated with ischemic cerebrovascular disease. In our case, we took special care concerning the following points to prevent ischemic complications. 1) The drilling of the temporal bone and a ventricular drainage were performed to ensure minimum retraction of the temporal lobe. 2) Retraction of the cortex was done intermittently to protect the brain from damage as much as possible. 3) Hypotensive conditions were avoided during and after surgery. 4) Continuous infusion of Nicardipine and hypertensive & hypervolemic therapy was started immediately to prevent any complication due to vasospasm. 5) Gentle surgery was carried out around the ischemic brain and vessels. The postoperative result suggested that our treatment to prevent postoperative ischemic complications due to complete occlusion of the right MCA was effective. In this paper we discussed the etiology of P2 portion aneurysm from the literature and by angiographical morphologies. In this case, the P2 portion aneurysm was considered to be produced by increase of hemodynamic stress to the PCA via fetal type PCo due to MCA occlusion. To our knowledge, this paper is the only report of PCA aneurysm associated with MCA complete occlusion brought about by SAH.