In operating on A. Corn. aneurysms by means of the pterional approach, there is no general agreement about the approach side, for many factors, such as the patient's dominant hemisphere, the A1 dominancy, the direction of the A. Con. A. and aneurysmal fundus, the operating surgeon's handedness, and any co-existing aneurysms or intracerebral and cisternal hematoma, must be taken in consideration.
Usually in cases of lt. A1 dominant, a more anterior position of rt. A1 than lt. A1, a rightward protrusion of the aneurysmal fundus and the presence of other co-existing aneurysms and intracerebral hematoma on the lt. side, the lt. pterional approach is recommended. In our hospital, however, we operated on all of the A. Com. aneurysms except the case which had other aneurysms on lt. ICA and/or MCA by means of the rt. pterional approach. We have now investigated the operation results.
We have found that the A1 dominancy and the direction of the A. Com. aneurysm and aneurysmal fundus are not the factors that should decide the approach side. The occurrence rate of post-operative psychiatric symptoms, such as Korsakoff's syndrome, personal change, and urinary incontinence, is significantly lower in the rt. pterional approach. In the case of a pre-rupture that needs a frontal lobectomy, the rt. pterional approach is better for management than lt., and it is not so difficult to evacuate the lt. frontal hematoma due to an A. Com. aneurysmal rupture by means of the rt. pterional approach.
Therefore, in the pterional approach, we have concluded that, in all cases of A. Com. aneurysms except having other aneurysms on lt. ICA and/or MCA, it is best to operate on them from the rt. side.
