OBJECTIVE Endoscopic transsphenoidal surgery has recently been introduced in pituitary surgery. We investigated outcomes and complications of endoscopic surgery in 2 referral centers in Korea.

METHODS We enrolled 134 patients with acromegaly (microadenomas, n = 15; macroadenomas, n = 119) who underwent endoscopic transsphenoidal surgery at Seoul National University Hospital (n = 74) and Samsung Medical Center (n = 60) between January 2009 and March 2016. Remission was defined as having a normal insulin-like growth factor-1 and a suppressed growth hormone (GH) <1 ng/mL during an oral glucose tolerance test.

RESULTS Remission was achieved in 73.1% of patients, including 13 of 15 microadenoma patients (86.7%) and 86 of 119 macroadenoma patients (72.3%). A multivariate analysis to determine a predictor of biochemical remission demonstrated that absence of cavernous sinus invasion and immediate postoperative GH levels <2.5 ng/dL were significant predictors of remission (adjusted odds ratio [OR], 5.14; 95% confidence interval [CI], 1.52-17.3 and OR, 9.60; 95% CI, 3.41-26.9, respectively). After surgery, normal pituitary function was maintained in 34 patients (25.4%). Sixty-four patients (47.7%) presented complete (n = 59, 44.0%) or incomplete (n = 5, 3.7%) recovery of pituitary function. Hypopituitarism persisted in 20 patients (14.9%) and worsened in 16 patients (11.9%). Postoperatively, transient diabetes insipidus was reported in 52 patients (38.8%) but only persisted in 2 patients (1.5%). Other postoperative complications were epistaxis (n = 2), cerebral fluid leakage (n = 4), infection (n = 1), and intracerebral hemorrhage (n = 1).

CONCLUSIONS Endoscopic transsphenoidal surgery for acromegaly presented high remission rates and a low incidence of endocrine deficits and complications. Regardless of surgical techniques, invasive pituitary tumors were associated with poor outcome.