Neck clipping in the acute stage of the basilar-tip aneurysm is one of the most difficult operations in aneurysm surgery, since the aneurysm itself is deep-seated and successful management after an occurrence of premature rupture is not easy. Therefore, a sufficient exposure of the operative field with lesser brain retraction is needed, particularly for a patient with impaired consciousness judged as grade 3 (or 4) (Hunt & Hess classification) at the time of operation. The so-called orbito-zygomatic approach representing detachment of the zygomatic arch for a distance of 3 to 3.5cm and removal of 3 to 3.5cm of the lateral orbital roof seems to be an excellent method in terms of successful exposure with lesser brain retraction, since the surgeon can see into the interpeduncular cistern obliquely from below.
A case reported here is that of a 52 year-old female who was admitted at emergency eight hours after an occurrence of sudden headache, vomiting and confusion. Neurological signs at admission showed moderately impaired consciousness (20, 3-3-3 Japanese Coma Scale), the right oculomotor paresis and nuchal rigidity. CT scan showed the presence of severe subarachnoid hemorrhage in the basal cisterns and angiogram revealed the presence of antero-laterally (to the right) positioned basilar-tip aneurysm, the rupture of which caused the right oculomotor paresis.
A direct operation was performed on the following day, since her consciousness had improved up to 3 (3-3-9 formula). Orbito-zygomatic approach from the left side (the opposite side from the aneurysm dome) was applied in order to avoid undesirable exposure of the aneurysm fundus during the approach to the aneurysm neck from the right side, and to avoid excessive retraction of the brain. The aneurysm neck was successfully clipped. The postoperative course was uneventful.
The orbito-zygomatic approach seems to be very useful for direct operation on a basilar-tip aneurysm in the acute stage, particularly when the aneurysm is located at a high position.
