破裂リスクスコアによる無症候性未破裂脳動脈瘤の手術適応の後方視的検討

抄録

The rupture-risk scoring systems, PHASES and UCAS, can numerically evaluate the risk of rupture of incidental unruptured cerebral aneurysms (UCA). We investigated 211 patients with UCA, diagnosed and treated for the past 4 years, using these risk-scoring systems and discussed the tendency and validity of our surgical indications retrospectively. When comparing 85 cases judged as surgical indications and 126 cases that became follow-up observations, the aneurysm size, aspect ratio, and the rate of irregularity (bleb) and growth of aneurysm were significantly higher in the surgery group, indicating that operations were performed in selected patients with a higher risk of rupture of UCA. When we compared the locations of the aneurysms in surgical cases, aneurysms arising from bifurcation of the anterior choroidal artery were significantly smaller and showed lower values of PHASES and UCAS scores than those of other locations, reflecting our treatment policy. The PHASES and UCAS scores effectively assist decision-making and surgical indication for UCA; however, the scores may not match the actual clinical judgment of rupture risks for the internal carotid artery aneurysms.