gms | German Medical Science

Objective: According to results of the International Study of Unruptured Intracranial Aneurysms (ISUIA) the rupture risk of asymptomatic aneurysms smaller than 7mm in the anterior cerebral circulation is 0%.

Goal of the present study was to register patients with primary known asymptomatic aneurysms smaller than 7mm in the anterior circulation, who subsequently developed a subarachnoid hemorrhage (SAH) due to secondary rupture of the known aneurysm.

Methods: Patients met following criteria were included in the present single center register: 1) Diagnosis of an incidental and clinically asymptomatic cerebral aneurysm of the anterior cerebral circulation smaller than 7 mm, 2) No direct or indirect radiological features of hemorrhage documented by MRI and CT-scan 3) SAH in the follow-up period due to rupture of the primary known incidental aneurysm.

Results: From 2005–2009 a total number of four patients met the inclusion criteria. Patient #1 is a 79-year-old female, harboring a 5.8mm anterior communicating artery (ACOM) aneurysm, which ruptured 53 months after initial diagnosis. Patient #2 is a 66-year-old male with a right-sided 5.8 mm middle cerebral artery (MCA) aneurysm, which ruptured 6 months after first detection. Patient #3 is a 57-year-old male with a 4mm ACOM aneurysm and subsequent rupture 2 months after initial diagnosis. Patient #4 is a 31-year-old-male diagnosed with a 4 mm ACOM aneurysm, which ruptured 12 months after initial diagnosis.

Conclusions: The present data suggests that there is a risk of rupture with consecutive SAH of primary incidental aneurysms smaller than 7mm in the anterior circulation. As a consequence the introduction of a multicenter registry with retro-and prospectively collected data would be of great interest to gain additional data for risk analysis.