Middle cerebral artery aneurysms: aneurysm angiographic morphology and its relation to pre-operative and intra-operative rupture.

Objective: Correlate the middle cerebral artery bifurcation aneurysm morphology with the pre-operative and intra-operative risk of rupture.

Methods: Forty patients with 46 middle cerebral artery bifurcation aneurysms were treated microsurgically by the same surgeon. Aneurysms were classified according to shape and the Fisher test was applied to analyze the effect of morphology on the pre-operative and intra-operative rupture.

Results: Pre-operative and intra-operative ruptures were observed in 8/46 patients (17.4%) and 14/46 patients (30.4%) respectively. Thirty-two cases (69.6%) had no symptoms postoperatively, modified Rankin score (MRS) of 0; 6.5% had MRS of 1 (no significant disability); 13% had MRS of 2 (slight disability); 4.3% had moderately severe disability (MRS of 4); and there were 3 deaths (6.5%) post-operatively. The morphology was not directly related to the rupture rate.

Conclusion: In general, ruptures are not affected by the morphology or the studied variables. Larger series are needed to validate these outcomes.