Anatomical and technical aspects of the contralateral approach for multiple aneurysms.

Microsurgery of multiple aneurysms is still a controversial subject. In order to avoid the risk of rebleeding and the consequent increase in morbidity in such cases all aneurysms or at least as many aneurysms as possible should be treated in the first operative procedure. To reach that goal aneurysms located on the contralateral side should also be considered for clipping during the first operation. Between 1984 and 1994 a series of 51 patients harboring multiple aneurysms of which 55 aneurysms were located on the contralateral side of the craniotomy were operated at our institution. No mortality or morbidity could be directly ascribed to the aneurysm that was clipped contralaterally. Based on that series we have described the anatomical features, technical aspects and surgical difficulties of approaching bilateral aneurysms through the same craniotomy.