The extended subcranial approach to the anterior skull base: modifications and combinations

The subcranial approach is becoming a single stage alternative to the classical craniofacial resection for tumors involving the anterior skull base. The advantages of this approach include the avoidance of facial incisions, minimal retraction of the frontal lobe, and wider exposure of the skull base from below. While in the majority of cases this approach allows circumferential exposure of the tumor, there are still cases in which extensions of particularly voluminous tumors are not easily reached by the subcranial approach. In cases of extensive inferior extensions into the lower nasal cavity, inferior maxillary walls, and maxillary antrum we elected to use a combined subcranial and midfacial degloving approach as a one-stage procedure. The addition of a unilateral pterional approach adds exposure to the most lateral aspects of the ipsilateral orbit, the retro-orbital region, as well as the sellar and chiasmatic regions. Dissection in the regions of the cavernous sinus is also made easier by this combined subcranial-pterional technique. We review the background of these two surgical combined approaches and describe the technique and limitations.