Surgical management of GH-secreting pituitary adenomas: An outcome study using modern remission criteria

The results of transsphenoidal surgery as initial therapy for GH-secreting pituitary adenomas in 57 acromegalic patients were analyzed retrospectively . Patients with prior surgery or radiation therapy were excluded from the s tudy. Three different criteria were used to define remission: glucose-suppr essed (nadir) GH less than 1.0 mug/liter, a normal sex- and age-adjusted IG F-I level, and postoperative random GH levels of 2.5 mug/liter or less. Add itionally, we analyzed the neuropathological data, including immunohistoche mistry and ultrastructural categorization, and the surgical complications. The short-term remission rate (6-wk postoperative follow-up visit), as dete rmined by a random GH measurement of 2.5 mug/liter or less, was 48.8%; the remission rate, as determined by nadir GH, was 51.4%. For 57 patients follo wed for 12 months or more after surgery (mean, 37.7 months), surgical remis sion was achieved in 70.2%, 66.7%, and 61.1%, respectively, for patients as sessed by normal IGF-I, random GH, and nadir GH. One patient (1.1%) develop ed recurrence of active acromegaly 81 months after initially successful sur gical therapy. Extrasellar growth of the tumor (P = 0.04) and dural invasio n by the adenoma (P = 0.008) were significant univariate predictors of a po or outcome. Tumor size was significantly greater in patients with persisten t or recurrent acromegaly (P = 0.02). Patients with tumors of the ultrastru ctural categories of mixed GH/PRL cell and mammosomatotroph adenomas had th e lowest remission rates (50% and 42.9%, respectively). There were no perio perative deaths, and there was no serious morbidity. The permanent complica tion rate was 3.3% (1 permanent DI and 2 nasal septal perforations). Surgic al management of acromegaly currently provides prompt, effective, and satis factory initial treatment for the majority of patients. Using stringent cri teria for remission, primary transsphenoidal surgery for GH-secreting pitui tary adenomas is effective and often definitive therapy for acromegaly. The se results provide a benchmark for the contemporary results of surgical man agement as assessed by modern outcome criteria.