1987 Volume 15 Issue 1 Pages 61-65
Direct clipping was performed in two cases of giant ophthalmic (30mm in diameter, subopticochiasmal global type) aneurysms in the right side who presented with visual disturbances in both eyes. Case 2 showed a second small aneurysm in the left IC-ophthalmic region. Preoperatively collateral circulation and tolerance to ischemia were studied by the Allcock and Matas tests. Both cases were operated on by right frontotemporal craniotomy. The neck carotid arteries were prepared for temporary occlusion during which time the brain function was monitored by scalp EEG. An STA-MCA anastomosis was performed before aneurysm surgery in Case 2.
The optic canal was opened and the anterior clinoid processes, which were well developed and pneumatized in both cases, were meticulously removed subdurally with an air drill. The anterior clinoid process in Case 1 continued to the middle clinoid process forming a bony canal around C3, which made the situation even more difficult. The cavernous sinus had to be opened around C3 in both cases in order to obtain space for the clip blade in the proximal neck of the aneurysm. Further dissection of the aneurysm from the surrounding structures such as the contralateral IC, optic nerve and chiasm could only proceed after the aneurysm had been decompressed by puncture, after which fenestrated clips could be applied without difficulty. Only one fenestrated and angled clip was applied in Case 1. Three fenestrated clips were needed in tandem manner in order to close the neck in Case 2. Here a fourth straight clip was necessary in order to stop continuous oozing, probably from the space between the tandem clips.
Postoperatively Case 1 returned to her normal household activities. Case 2 was blinded in her right eye and showed dense left hemiparesis, for which she is receiving rehabilitation at four months after the surgery. CT showed an infarction in the territory of the right anterior choroidal artery.
Discussions are presented about 1) choice of treatment, direct or IC occlusion with bypass surgery; 2) ischemia monitors and brain protection during temporary occlusion of the IC; 3) importance of opening the cavernous sinus in order to obtain the proximal neck of the aneurysm; 4) importance of protection of the posterior communicating, anterior choroidal and perforating arteries, especially when fenestrated and angled clips are applied.
