Variations of Approaches to the Anterior Base of the Skull

Abstract

There are different ways to approach a lesion of the anterior base of the skull depending on its location and extension. We differentiate between extracranial, intracranial, and combined approaches. The extracranial approach can be performed as an endonasal, transfacial subcranial, or midfacial degloving procedure. In addition to the tumor extension and its exposure, the criteria for choosing the appropriate access must include the operative procedure, for example, en bloc resection, piecemeal resection, or additional reconstruction. Furthermore, surgical safety concerning potential complications and radicality play a major role alongside morbidity and aesthetic considerations. Thus transfacial approaches should be avoided if alternative endonasal or midfacial degloving procedures may be performed. If transfacial incisions cannot be avoided, the aesthetic components and relaxed skin tension lines must be considered. The midfacial degloving procedure is a very suitable approach to the paranasal sinuses and the anterior skull base. In particular, the pterygopalatine fossa, the nasopharynx, and the pterygoid process can be well exposed. The surgical exploration reaches far lateral right into the infratemporal fossa. If the ventral region of the anterior base of the skull is involved, midfacial degloving reaches its limit. In these cases, subcranial approaches or the midfacial degloving in combination with a transcranial transfrontal approach are preferable. The transfrontal approach in combination with an otorhinolaryngological access in cooperation with neurosurgeons is necessary if the tumor penetrates the dura or has pushed the dura into the endocranium.