Objective: : The endoscopic endonasal transsphenoidal approach is a widely-used method for the surgical treatment of pituitary adenomas. We aimed to evaluate the results of endoscopic surgery by comparing preoperative classification methods and investigating their relationship with postoperative resection and remission rates and complications. Methods: : We retrospectively reviewed the medical records of 236 patients (118 males) who underwent surgery for pituitary adenomas. Preoperative Knosp classification, tumor size (TS), suprasellar extension (SSE), postoperative resection and remission rates, and complications were evaluated. Results: : The follow-up period was 3 months to 6 years. The patients’ ages ranged between 16 and 84 years. Endocrinologically, 114 patients (48.3%) had functional adenoma (FA), and 122 patients (51.7%) had non-functional adenoma (NFA). Among the FA group, 92 (80.7%) showed remission. A statistically significant difference was found between patients with and without remission in terms of the Knosp, TS, and SSE classifications (p<0.01). Knosp, TS, and SSE classification grades were found to be correlated with the resection rates (p<0.01). Meningitis was seen in seven patients (3.0%), diabetes insipidus in 16 (6.9%; permanently in two [0.9%]), and rhinorrhea in 19 (8.1%). Thirty-six patients (15.3%) developed pituitary insufficiency and received hormone replacement therapy. Conclusion : The resection categories and remission rates of FAs were directly proportional to the adenoma sizes and Knosp grades, while the degree of suprasellar growth further complicated resection and remission rates. Adenoma sizes less than 2 cm and SSEs less than 1 cm are associated with favorable remission and resection rates.

Objective: : The endoscopic endonasal transsphenoidal approach is a widely-used method for the surgical treatment of pituitary adenomas. We aimed to evaluate the results of endoscopic surgery by comparing preoperative classification methods and investigating their relationship with postoperative resection and remission rates and complications. Methods: : We retrospectively reviewed the medical records of 236 patients (118 males) who underwent surgery for pituitary adenomas. Preoperative Knosp classification, tumor size (TS), suprasellar extension (SSE), postoperative resection and remission rates, and complications were evaluated. Results: : The follow-up period was 3 months to 6 years. The patients’ ages ranged between 16 and 84 years. Endocrinologically, 114 patients (48.3%) had functional adenoma (FA), and 122 patients (51.7%) had non-functional adenoma (NFA). Among the FA group, 92 (80.7%) showed remission. A statistically significant difference was found between patients with and without remission in terms of the Knosp, TS, and SSE classifications (p<0.01). Knosp, TS, and SSE classification grades were found to be correlated with the resection rates (p<0.01). Meningitis was seen in seven patients (3.0%), diabetes insipidus in 16 (6.9%; permanently in two [0.9%]), and rhinorrhea in 19 (8.1%). Thirty-six patients (15.3%) developed pituitary insufficiency and received hormone replacement therapy. Conclusion : The resection categories and remission rates of FAs were directly proportional to the adenoma sizes and Knosp grades, while the degree of suprasellar growth further complicated resection and remission rates. Adenoma sizes less than 2 cm and SSEs less than 1 cm are associated with favorable remission and resection rates.

Objective: : Postoperative data on Cushing’s disease (CD) are equivocal in the literature. These discrepancies may be attributed to different series with different criteria for remission and variable follow-up durations. Additional data from experienced centers may address these discrepancies. In this study, we present the results obtained from 96 endoscopic transsphenoidal surgeries (ETSSs) for CD conducted in a well-experienced center. Methods: : Pre- and postoperative data of 96 ETSS in 87 patients with CD were included. All cases were handled by the same neurosurgical team between 2014 and 2022. We obtained data on remission status 3−6 months postoperatively (medium-term) and during the latest follow-up (long-term). Additionally, magnetic resonance imaging (MRI) and pathology results were obtained for each case. Results: : The mean follow-up duration was 39.5±3.2 months. Medium and long-term remission rates were 77% and 82%, respectively. When only first-time operations were considered, the medium- and long-term remission rates were 78% and 82%, respectively. The recurrence rate in this series was 2.5%. Patients who showed remission between 3−6 months had higher longterm remission rates than did those without initial remission. Tumors >2 cm and extended tumor invasion of the cavernous sinus (Knosp 4) were associated with lower postoperative remission rates. Conclusion : Adenoma size and the presence/absence of cavernous sinus invasion on preopera-tive MRI may predict long-term postoperative remission. A tumor size of 2 cm may be a supporting criterion for predicting remission in Knosp 4 tumors. Further studies with larger patient populations are necessary to support this finding.