Abstract
Aneurysms arising at the P3 portion of the posterior cerebral artery are relatively rare. They represent 0.3%of all cases of cerebral aneurysms and 3.1%of posterior circulation aneurysms. Operative approaches to aneurysms at this portion have been reported by only a few authors.
We have experienced clipping of the aneurysm at this portion through an occipital interhemispheric approach with the patient positioned in a lateral recumbent, operated-side-down posture. We discuss the advantages and disadvantages of this approach in our current report.
An occipital interhemispheric approach has many advantages. It sacrifices less bridging veins. It makes for a more comfortable posture with a wider working space for the surgeon and assistants to carry out the operation. However, it is the disadvantage of a risk of post-operative homonymous hemianopsia.
We were careful to eliminate pressure on the striate cortex so that visual field defect could be prevented. We placed the patient with the operated side down so that the occipital lobe of the affected side subsides naturally from its own weight.
