Retrospective analysis of the outcomes of endoscopic transsphenoidal surgery for Cushing's disease.

ABSTRACT

Background: The first-line surgical management of an adrenocorticotropic hormone (ACTH)--secreting pituitary adenoma causing Cushing's disease (CD) is endoscopic transsphenoidal resection of the tumor. This study was performed to assess postoperative (postop) complications and remission in endoscopic surgically resected cases of CD. Methods: Data of patients who underwent endoscopic transsphenoidal surgery (ETSS) for CD were collected from the neurosurgery department at a tertiary care center in a retrospective manner from January 2015 to February 2022 and analyzed. Postoperative remission was categorized as - early morning serum cortisol <138 nmol/L within 7 days of the surgery, as per the Endocrine Society Guidelines, with significant clinical improvement in features of hypercortisolism in the operated patient and strict cutoff rate of <50 nmol/L at postop day 3 was also utilized, to look for the early identification of remission. Results: A total of 41 patients were identified who underwent 44 ETSS during the same timeframe. Preoperative magnetic resonance imaging localized an adenoma in all 41 patients, out of which 32 were microadenoma, and nine were macroadenoma (2 with cavernous sinus invasion). Intrapetrosal sinus sampling was performed in 35 (85%) patients. The rate of remission for the initial surgery was 85.4% using the standard criteria and 68.3% using strict criteria. Three patients underwent early repeat surgery for the persistent disease as the day 3 cortisol was high (306-555 nmol/L). Once the outcome of this surgery was also included, the overall rate of remission was 90.2% (37/41). None of the patients had meningitis, cerebrospinal fluid leakage, visual deterioration, or vascular injury. Permanent and transient diabetes insipidus (DI) occurred in 9.75% and 26.8% following the first ETSS, respectively. We also noted a single case of CD recurrence in 9 months during the total follow-up period of 84 months. Conclusion: ETSS has satisfactory rates of remission for the primary treatment of CD, with rates being higher for microadenomas. A long follow-up period is needed to assess the rates of recurrence. Patients must be counseled regarding the risk of postop DI, whether transient or permanent, as a possible complication.