Modifications and combinations of the extended subcranial approach to the anterior skull base

Introduction: The subcranial approach is becoming a single stage alternative to the classical transcranial-transfacial approaches for lesions 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 provides additional 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. In addition to the combined subcranial facial degloving and subcranial-pterional techniques we will also describe a transnasal endoscopie approach coupled with the subcranial route and transorbital-subcranial combination without the use of a bicoronal flap. Conclusion: These combinations as described by us were performed in 13 patients. The surgical technique will be detailed and the complications and outcome will be presented. It is concluded that these approaches provide an important adjunct in the armamentarium of the skull base surgeon for the management of targeted problems.