[New operative approach to the frontal base. Extensive transbasal approach]

Lesions in the frontal base have been conventionally approached extra- and intradurally through a bilateral frontal craniotomy. However, when the lesion is large or deeply situated, wider retraction of the bilateral frontal lobes is required to obtain a sufficient operative field. The authors describe a new operative approach to dumbbell-shaped tumors in the frontal base, consisting of en bloc osteotomy of the bilateral orbital roofs and frontal sinus. This procedure, which is a modification of the transbasal approach described by Derome, is termed the "extensive transbasal approach." Successful applications of this procedure in three patients with frontal base tumors, two with frontal base fractures, one with a frontal arteriovenous malformation, and one with a frontal sinus mucocele are described. Also, the advantages of this approach over other, conventional operative approaches are discussed.