It is sometimes difficult to make a diagnosis of the ruptured site in the case of multiple intracranial aneurysms. We retrospectively analyzed 21 ruptured cases with multiple aneurysms, focusing on the following 4 factors.
1. SAH localization: A CT scan was available for localizing the ruptured site in 13 (62%) patients.
2. Size of aneurysm: The ruptured aneurysm was larger than the unruptured aneurysm in 12 (57%) patients.
3. Shape of aneurysm: The ruptured aneurysm was irregularly shaped in all patients, whereas the unruptured aneurysm in 10 (34%) was irregularly shaped and in 19 (66%) was round.
4. Aspect ratio of aneurysm: The aspect ratio of ruptured aneurysms was larger than that of unruptured aneurysms in 20 (95%) patients.
To identify the ruptured aneurysm in the patient of multiple aneurysms, it is important to consider many factors, especially the aspect ratio of the aneurysm.