Functional Outcomes in Endoscopic Endonasal Surgery of the Skull Base, A rising challenge

Extended endonasal endoscopic approaches (EEEA) for skull base lesions have been increasing over the last decade. Determinants for this development are the enhanced understanding of the endoscopic anatomy, improvement of imaging systems and specific instruments, and the use of vascularized flaps for reconstruction [1]. This EEEA can cause postoperative morbidity related to the reconstruction, like crusting and posterior rhinorrhea, especially in those cases requiring an endonasal flap [2,3]. The healing process start the first week with a reepithelization by stratified epithelium, then hair cells appear in the third week and complete recovery of the sinus epithelium occurs within 6-8 weeks [4]. Given this, [5] conclude that one must wait at least three months to assess the clinical and postoperative symptoms. Regarding quality of life (QOL) after EEEA evidence have shown that the morbidity is related to the extension of the approach. [6] reported a negative impact in QOL after the use of nasoseptal flap which is commonly associated to extended approaches. The latter was mainly due to an increased tendency to headaches and reduced smell; however, recovery occurs over time especially in those patients with secreting pituitary tumors. Since the use of endoscopic skull base surgery, there have been great efforts to develop specific QOL questionnaires for EEEA and pituitary surgery (Table 1) Until now, the following tests have been applied in English literature; Quality of Life-Assessment of Growth Hormone Deficiency in Adults [7], Hypopituitarism Quality of Life Satisfaction (QLS-H) [8], Previous Skull Base Quality of Life (ASB-QOL) [9], Hormone Deficiency-Dependent Quality of Life ( HDQOL) [10], Acromegaly Quality of Life (ACROQOL) [11], Pituitary Adenoma Quality of Life (PA-QOL) [12], Cushing Quality of Life [13], Addison Quality of Life (AddiQOL) [14], or ASK nasal inventory [15]. Handicaps for these tests are that they do not include specific areas about quality of life and cancer, visual defects, hormonal deficiency or sinonasal symptoms. Here, we will discuss the impact of EEEA regarding the following topics: