Endonasal surgery of the anterior skull base

Abstract

There has been an impressive evolution in endoscopic skull base surgery over the past few years. The rhinologist has emerged as an important member of the interdisciplinary skull base team as experience has grown in the use of less invasive techniques to remove sinus tumours. Endonasal endoscopic approaches have become the standard for the surgical treatment of inflammatory sinus diseases and benign sinus tumours over the past few years. Although endoscopic resection of malignant tumours has been controversial, there is increasing evidence that there are many advantages to the endoscopic approach to remove many nasal and skull base tumours. The fundamental reasons behind this evolution are the new knowledge about the anatomy from the endoscopic perspective, and the development of instruments and image guidance that allow a more direct and magnified vision of what the surgeon can do (Fig. 8.1). A reduction in the mortality and morbidity – including less disruption of the brain and eye – of the surgery, being able to deal with most complications, a recognition that an ‘en bloc’ resection of most skull base tumours was a good concept but is rarely achievable, thus negating one of its main raisons d’être, and an accumulating volume of evidence add weight to the use of the endonasal approach in skull base surgery.1,2The management of tumours of the skull base must be done as part of a multidisciplinary team and the surgeon should be able to undertake an external approach and know how to deal with the majority of possible complications (Fig. 8.2). This includes being able to change to an external approach if necessary at any time during procedure. The following principles apply to the planning of an endoscopic procedure of the skull base:l understanding the pathology of any lesion of the skull base is essential in its managementl involvement of other relevant disciplines in making a treatment planl extensive range of equipment is needed to do this type of surgeryl imaging should be done to define the extent of any tumour and when it is very vascular, angiography can contribute regardless of whether or not there is preoperative embolizationl preoperative counselling is important.