ABSTRACT
This paper first goal is to establish what "critical" aneurysm means. We decided to consider as "critical" aneurysms those whose correct clipping-treatment would be particularly difficult; this particular difficulty could concern the malformation intrinsic characteristics as well as extrinsic factors (the patient's clinical conditions as well as insufficient organizational or technical facilities). We thus reviewed 277 aneurysms operated in the Neurosurgical Department of Varese from 1988 to 1994. We excluded 18 vertebro-basilar system aneurysms; the clinical and surgical charts of the 259 remaining aneurysms were reviewed and informations regarding their last clinical conditions were gathered. In this way it was possible for us to distinguish different categories of critical aneurysms: critical for their anatomical position, morphology, size and for their number; unpredictably critic aneurysms and aneurysms associated with the patient's critical conditions were also considered. After describing our technical solutions and those suggested by the current literature we concluded that what is required to treat these critical aneurysms is not an extraordinary surgical skill, but a good organizational and technical facility at the surgical-team's disposal.
