Direct surgical approach to infraclinoidal aneurysms.

A loose connective tissue layer covering the intracavernous portion of the internal carotid artery makes the exposure of the anterior syphon knee possible without opening the cavernous sinus. The approach leads by a fronto-latero-basal craniotomy to the anterior part of the cavernous sinus roof (transversal plate). The anatomical relationships are discussed. By means of surgical cases, both the ipsilateral and the contralateral approach to infraclinoidal aneurysms are demonstrated.