Surgical outcomes of endoscopic endonasal transsfenoidal surgery in acromegaly and predictive factors of endocrinological remission

OBJECTIVE:Acromegaly is a disease of acral enlargement and elevated serum levels of insulin-like growth factor-1 (IGF-1) and growth hormone (GH), usually caused by a pituiter adenoma. A lack of concensus of factors that reliably predict outcomes in acromegalic patients following endoscopic endonasal trannsfenoidal surgery requires additional investigation. In this study, we assessed biochemical outcome of endoscopic endonasal surgery in growth hormone-secreting adenomas, including remission rate, predictors of remission. MATERIALS AND METHODS: We identified 47 patients with acromegaly who underwent an endoscopic endonasal approacah for resction of a GH- secreting pituitary adenoma. Pre operative and postoperative tumor and endocrinological characteristics such as tumor size, invasiveness, GH/IGF-1 levels, histopathologic subtypes were evaluated as potential indicators of postoperative hormonal remission. The criteria of remission was post operative growth hormone levels < 1 µg/L and normal age-adjusted insulin like growth factor-1 concentration within the first 6 months after surgery. RESULTS: The 47 patients had a mean age of 45,0 ±9,7 years and a mean follow up duration 21,6±2,6 months. 10 patients (%21,3) had microadenomas and 36(%76,6) had macroadenomas, 1 patient (%2,1) had giant adenoma. Twelve tumors (%25,5) were invading cavernous sinuses. 27 patients (%57,5) underwent gross total resection (GTR) and 20(%42,5) underwent subtotal resection. 31 patients (%68) achieved hormonal remission after endoscopic endonasal transsfenoidal surgery (EETS) alone. This rate increased to %76,5 with adjunctive medical therapy. Biochemical remission was achieved 7 of 10 microadenomas (%70) and 29 of 37 macroadenomas (%78,4). Female gender, post operative day 1 (POD1) GH levels, extent of resection were correlatedwith hormonal remission. No significant correlations were found between hormonal remission and age, pituitary adenoma subtype, tumor size or invasiveness. CONCLUSIONS: Endoscopic endonasal transsfenoidal resection of GH secreting pituitary adenomas is a safe and highly effective treatment for achieving hormonal remission and tumor control. Female patients, patients who have lowers POD1 GH levels and patients who undergo GTR are more likely to achieve postoperative biochemical remission. KEYWORDS: Pituitary Adenoma, Acromegaly, Endoscopic transsfenoidal surgery, Remission