Long-Term Effects of Intracapsular Debulking and Adjuvant Somatostatin Analogs for Growth Hormone-Secreting Pituitary Macroadenoma: 10 Years of Experience in a Single Institute

Objective Long-term effects of endoscopic endonasal transsphenoidal intracapsular debulking and adjuvant somatostatin analogs (SSAs) were evaluated in patients with growth hormone- (GH) secreting pituitary macroadenomas. Methods We retrospectively reviewed the medical records of 45 patients with acromegalic macroadenoma who underwent endonasal endoscopic transsphenoidal intracapsular debulking and received adjuvant SSAs (octreotide) between 2006 and 2015 who had >1 year of follow-up. To evaluate the predictive factors for 1 year and long-term biochemical outcomes, univariate and multivariate analyses were performed. Results Biochemical remission was achieved in 1 year in 20 of the 45 (44.4%) patients, and in 31 of the 45 patients after long-term adjuvant SSA treatment. Tumor control was achieved in 43 of the 45 (93.3%) patients. The univariate analysis showed age (≥55 years), tumor size (diameter ≤1.5 cm), premedication GH levels (≤2.8 ng/mL), premedication insulin-like growth factor 1 levels (≤2-fold of upper limit of normal range), cavernous sinus invasion (Knops grades 2, 3, and 4), and near-total tumor resection were associated with long-term outcomes. The multivariate analysis showed near-total resection was a significant predictor for long-term outcomes ( P  = 0.019). There were no new pituitary dysfunctions. The observed complications included one case of cerebrospinal fluid leakage and one case of epistaxis requiring intervention. Conclusions Intracapsular debulking and adjuvant SSAs are a safe and viable treatment for patients with GH secreting pituitary macroadenoma to achieve biochemical remission and tumor control. Although adjuvant SSA treatment enhances residual tumor control, cavernous sinus invasion impedes the remission of endocrine tumors.