Unilateral interhemispheric keyhole approach for anterior cerebral artery aneurysms.

A special midline interhemispheric keyhole approach to the anterior communicating artery aneurysms is described. A small trephine opening of 3 cm in diameter is used in most cases. The detailed microsurgical technique of the unilateral interhemispheric exposure of the anterior cerebral artery complex is presented. For the past 10 years, a total of 138 patients, 112 with Acom AN and 26 with distal ACA AN, were operated upon through this approach. There were 16 cases with non-ruptured aneurysms and the postoperative results were excellent in all of them. The overall results in 122 cases with ruptured aneurysms were excellent and good (working) in 95 cases, fair in 10 cases, poor in 9 and death supervened in 8 cases. The mortality rate in 71 acute operation cases was 8% and 4% in 51 delayed cases. The advantages of this approach include simple and rapid craniotomy, minimum brain retraction, accurate midline exposure of all parent arteries and the aneurysm. This anterior interhemispheric approach is, in our experience, much superior to the conventional pterional approach.