Surgical and endocrinological outcomes in the treatment of growth hormone-secreting pituitary adenomas according to the shift of surgical paradigm

BACKGROUND:: Extensive data exist regarding the success rates and long-term outcomes of transsphenoidal adenomectomy (TSA) of growth hormone (GH)-secreting pituitary tumors; however, few data exist regarding the extent of adenomectomy. OBJECTIVE:: To evaluate surgical outcomes for the treatment of GH-secreting pituitary adenomas with regard to the extent of adenomectomy. METHODS:: A retrospective study of 282 patients with GH-secreting pituitary tumors who underwent TSA. Three surgical paradigms (1, 2, and 3) were applied, all of which differed in extent of adenomectomy. All participants were evaluated with oral glucose tolerance tests (OGTTs) at 6-month intervals for 1.5 years and combined pituitary function tests at 1.5-year intervals after TSA. All surgeries were conducted by a single neurosurgeon at a single medical center. Biochemical remission was defined with insulinlike growth factor 1 and OGTT results. RESULTS:: The overall surgical remission rates were 89%, 87%, 64%, 70%, and 50% (nadir GH <1 ng/mL on OGTTs: 96%, 95%, 73%, 84%, and 56%) for modified Hardy classifications I, II, IIIA, IIIB, and IV, respectively. The remission rates for modified Hardy classification I-IIIB improved to 42%, 68%, and 84% after application of surgical paradigms 1, 2, and 3, respectively (P = .002). Aggressive surgical resection did not worsen hypopituitarism. Among the 42 patients with modified Hardy classification IV, 24 (57%) achieved remission without recurrence after applying the aggressive paradigm 3 surgery. CONCLUSION:: An aggressive surgical approach may be critical to managing GH-secreting pituitary adenomas and does not increase the risk of postoperative hypopituitarism.