EXPANDED ENDOSCOPIC ENDONASAL APPROACH FOR ANTERIOR CRANIAL BASE AND SUPRASELLAR LESIONS: INDICATIONS AND LIMITATIONS

OBJECTIVE: The traditional boundaries of the transsphenoidal approach can be expanded to include the region from the cribriform plate of the anterior cranial fossa to the foramen magnum in the anteroposterior plane. The introduction of endoscopy to transsphenoidal surgery, with its improved illumination and wider field of view, has added significant further potential for the resection of a variety of cranial base lesions. We review our experience with the expanded endoscopic endonasal approach in a series of 22 patients with anterior cranial base and supradiaphragmatic lesions. METHODS: From June 2005 to June 2007, the expanded endoscopic endonasal approach was used in 22 patients with the following pathologies: 6 craniopharyngiomas; 4 esthesioneuroblastomas; 3 giant pituitary macroadenomas; 2 suprasellar Rathke's Pouch cysts; 2 angiofibromas; and 1 each of suprasellar meningioma, germinoma, ethmoidal carcinoma, adenoid cystic carcinoma, and large suprasellar arachnoid cyst. This study specifically focused on the surgical indications and approaches to these lesions and the surgical results, complications, and limitations associated with this technique. RESULTS: Gross total tumor removal, as assessed by postoperative magnetic resonance imaging, was possible in the majority of patients (73%), with the exception of the craniopharyngioma group, in which only I lesion was completely removed. There were no permanent neurological complications except for increased visual disturbance in 1 patient. Other complications included cerebrospinal fluid fistulae in 4 patients (18%) and meningitis in 1 patient (5%). There was no operative mortality. Large lesions, significant lateral extension, encasement of neurovascular structures, and brain invasion in malignant lesions are considered some of the contraindications for this technique. CONCLUSION: The expanded endoscopic endonasal approach is a promising minimally invasive alternative to open transcranial approaches for selective lesions of the midline anterior cranial base. The avoidance of craniotomy and brain retraction and reduced neurovascular manipulation with less morbidity are potential advantages. Major complications have been few, but there are also limitations with this technique. This approach should be included in the armamentarium of cranial base surgeons and considered as an option in the management of selected patients with these complex pathologies.