内頚後交通動脈分岐部動脈瘤切迫破裂として緊急治療した症例の臨床症状と画像所見

抄録

Background: Traditionally, unruptured internal carotid-posterior communicating artery aneurysms (IC-PC ANs) with oculomotor nerve palsy (ONP) have been considered at a relatively high risk of future rupture. Therefore, surgical treatment is urgently indicated to prevent the presumed impending subarachnoid hemorrhage (SAH). In this article, we reviewed our experiences with IC-PC AN cases diagnosed as impending rupture.

Materials and Methods: We treated 10 patients from December 2012 to April 2017. We reviewed their clinical characteristics and aneurysm images.

Results: The initial symptoms were ptosis or double vision in 3 patients (30%), ipsilateral deep orbital or temporal pain in 5 (50%), and upset eye in 4 (40%). In their first visit to our hospital, 9 patients (90%) had ONP and 7 (70%) had ipsilateral deep orbital pain or temporal pain. All patients underwent successful microsurgical clipping or intravascular embolization and discharged with a modified Rankin scale score of 0 or 1. The mean IC-PC AN diameter was 6.9±2.9 mm. The ANs were irregular in shape and had multiple blebs in all the patients. Furthermore, many ANs had blebs projecting over the top of the ANs; hence, aspect ratios tended to be relatively high (mean, 2.8±1.0). In the surgical clipping cases, we confirmed that the AN blebs seemed extremely fragile and had very thin walls, and intraoperative aneurysm rupture occurred in 3 cases.

Conclusion: In addition to ONP, ipsilateral deep orbital pain or focal headache is an important sign of impending IC-PC AN rupture. Furthermore, the irregular shape, multiple blebs, and projecting bleb over the top of the AN may be characteristic features indicating impending rupture.