抄録
Clipping of the internal carotid artery (ICA)-paraclinoid aneurysm is well known to be associated with a risk of visual impairment. However, whether visual function is influenced more by anterior clinoidectomy or by other procedures is still controversial. In this study, the impact of each procedure on visual function was evaluated by monitoring visual evoked potential (VEP). Between January 2008 and September 2016, 52 ICA-paraclinoid aneurysms were treated with clipping or trapping. All the surgeries for treating the aneurysms were performed from the ipsilateral side irrespective of their projection. After craniotomy, anterior clinoidectomy was performed extradurally only with a micro-rongeur to avoid heat injury. A clip was placed to avoid interrupting blood flow in the ophthalmic and superior hypophyseal arteries. VEP was monitored with light-emitting diode flashing silicone electrodes concomitant with electroretinography monitoring to confirm the stimulus to the retina. All aneurysms were clipped or trapped completely. Postoperative visual deterioration occurred in two cases (3.8%). VEP could be monitored in 42 cases (81%). During anterior clinoidectomy, change in VEP was observed in 11 cases but was transient in all the cases and did not affect the outcomes. Two of seven cases with permanent change in VEP after dural opening had a postoperative visual deficit. In conclusion, VEP monitoring is effective for predicting visual outcome if done reliably.
