gms | German Medical Science

Objective: Nowadays coiling is regarded as the first choice treatment option for asymptomatic aneurysms in many centres. However, innocent middle cerebral artery (MCA) aneurysms are frequently treated by microsurgical clipping due to their often unique anatomical features. If subjected to clipping procedure, these patients' outcome might then be compromised by a preselection bias. In order to characterize the anatomical features of this special group of aneurysms and compare clinical and angiographical results with large patient collectives of former studies we conducted a retrospective analysis of our experience.

Methods: We analyzed a series of 87 patients admitted to our department between 2006 and 2010 harbouring MCA aneurysms not approachable by coiling. Reasons for subjection to clipping were reviewed. Anatomical features as depicted by the initial angiography were analyzed. Clinical outcome was assessed using the Glasgow Outcome Score (GOS). Postoperative ischemic events were detected by computerized tomography (CT). Securing of aneurysm was controlled by digital subtraction angiography.

Results: Average patient age was 53.7 years (range, 29–73 year); 65 were women and 22 were men. 33 aneurysms were located on the left side, 54 on the right. There were 65 bifurcation aneurysms, 12 M1 aneurysms, 4 M2 Aneurysms, 1 M3 aneurysm and 5 trifurcation aneurysms. The average aneurysm size was 8.3 mm (range, 2.0–50.0 mm). Aneurysm neck was wide in 70 cases. Single or multiple branches arising from the aneurysm were found in 48 patients. Decision for clipping was mainly made because of: neck size in 15 cases, neck size and arterial branches in 22 cases, small aneurysm size in 7 cases, arterial branches in 12 cases, generalized arteriosclerosis in 5 cases, unclear angiographic situation in 3 cases and various reasons in 23 cases. Postoperative ischemic minor events were diagnosed in 11 patients. In 20 patients postoperative angiography showed that clipping of the aneurysm was incomplete with persisting basal perfusion. GOS was good (4–5) in 86 patients and poor (3) in one patient.

Conclusions: Overall clinical outcome is excellent. Although preselection of patients is apparent and anatomical configuration of the MCA aneurysm seems more complex, outcome is comparable to previous studies of surgically treated patients. The anatomy of the (preselected complex) aneurysms often compromises the complete clipping of these aneurysms.