To study the clinical characteristics and the diagnostic value of the computed tomography angiography (CTA) and the effects of microneurosurgical management for the mirror-image aneurysm of middle cerebral artery (MCA).

The clinical data of 15 cases with mirror-image aneurysms of MCA which by 64 rows helical CTA diagnosed and underwent microneurosurgical operation were analysed retrospectively. A total of 32 aneurysms (including 2 posterior communicating aneurysms) were detected by 64 rows helical CTA and all the mirror-image aneurysms located in MCA bifurcation. The mirror-image aneurysms of MCA were treated through the method of combining early-stage with select-stage operation and one-stage with two-stage operation. The operating principle was the ruptured aneurysm performed treated first and the unruptureed aneurysm performed treated second.

Nine cases performed one-stage operation and 20 aneurysms were clipped (including 2 posterior communicating aneurysms), in which 4 cases intracerebral hematomas were removed in the same time. 4 cases performed two-stage operation and 4 aneurysms were clipped at first, in which 2 intracerebral hematomas were removed in the same time, and 4 aneurysms were clipped at second operation. One side aneurysm was clipped and another side aneurysm did not treat in 2 cases. Acording GOS scale to jude: 5 points, surgical outcome were good in 10 cases; 4 points, light disability in 4 cases and 3 points, severe disability in 1 case.

The 64 rows helical CTA is a accuracy and reliable examinational method for detecting the mirror-image aneurysm of MCA. It can help to determine the responsibility aneurysm of ruptured aneurysms if the mirror-image aneurysm of MCA had been divided into Ⅰ model (perfectly symmetry model) and Ⅱ model (in perfectly symmetry model). The microneurosurgery was the effective and reliable method to treat the mirror-image aneurysm of MCA.