Abstract
Expanded endoscopic endonasal approaches (EEAs) have significantly advanced the surgical management of invasive pituitary tumors that extend beyond the sella turcica. They are particularly important in functioning tumors to achieve biochemical remission. In this article, we review the classification and application of expanded EEAs in addressing tumors invading the anterior skull base, suprasellar cisterns, clivus, and cavernous sinus. The anatomical basis, techniques, and indications for the endoscopic endonasal transtuberculum-transplanum, transclival, and transcavernous approaches, as well as the resection of the medial wall of the cavernous sinus, are discussed. The outcomes of these approaches are reviewed and our surgical strategy for these tumors is presented. Despite advances in technology and our understanding of the parasellar anatomy, we emphasize the importance of a multidisciplinary team and graded experiential learning for surgeons to minimize the complication rates associated with these technically advanced approaches.