Objective: Recently, we often encounter patients aged 80 years and over with unruptured aneurysms in Japan. But, we don’t know the best way to follow up such patients. This study describes to find a new guideline of the patients’ follow-up from recent trends in our cases.
Methods: Between 2007 and the first half of 2017, we encountered 158 patients aged 80 years and over with unruptured aneurysms. We divided them into two groups; the patients pointed out unruptured aneurysms before (pre-80 group) and after (post-80 group) 80 years old. We detected whether we followed up, duration of the follow-up, age at the diagnosis (post-80 group), reason for stopping the follow-up, and the site, size, and growth of aneurysms. 
Results: We followed up 91 patients between two groups. The patients’ average age at the diagnosis (post-80 group) was 82.3 years. The average duration of the follow-up was 4.0 years in pre-80 group and 2.6 years in post-80 group. Among the follow-up patients, we operated 3 cases, and the site of the aneurysms was internal carotid artery in all cases. 
Conclusion: The outcome is poor in patients aged 80 years and over with subarachnoid hemorrhage. If we can prevent the rupture of the aneurysms in such patients efficiently, it is suitable for medical economy. The report described previously indicates that aneurysms of internal carotid artery were often ruptured in the aged patients. This demonstrates that we may follow up the patients with internal carotid artery aneurysms until about 85 years old.

Consideration of patients aged 80 years and over with unruptured aneurysms in Japan