Abstract
There are two major approaches to a basilar bifurcation aneurysm, the subtemporal approach developed by Drake, and the pterional approach developed by Yasargil. In either approach, however, it is hazardous and difficult to approach a basilar bifurcation aneurysm with a megadolichobasilar anomaly because strong retraction of the brain, nerves and vessels is required.
Two successful cases of a ruptured basilar bifurcation aneurysm with a megadolichobasilar anomaly treated directly through the third ventricle are reported in this paper.
A 62-year-old woman and a 60-year-old woman were admitted with disturbance of consciousness.
Their plain CT scans on admission demonstrated massive and diffuse subarachnoid hemorrhage and clots in the third ventricle.
Their left vertebral angiographies demonstrated basilar bifurcation aneurysms which were considered to be inaccessible by conventional approaches because of their high position. Therefore, we applied the new approach described below.
The operation was performed at an acute stage, using a bifrontal craniotomy. Dissecting interhemispheric fissure, we approached the third ventricle via the lamina terminalis. After evacuating the clot in the third ventricle, the basilar bifurcation aneurysm could be visualized. After opening the floor of the third ventricle at the midline to dissect the neck of the aneurysm and perforating arteries, clipping was performed.
The postoperative courses were uneventful.
The key surgical points and the prospective view in approaching via the lamina terminalis and through the third ventricle for a high position basilar bafurcation aneurysm are discussed in this paper.
