Analysis Of Factors Affecting The Outcome Of Transsphenoidal Surgery In Patients With Growth Hormone-secreting Pituitary Adenoma

OBJECT: To investigate factors related to the post-operative remission in patients with growth hormone-secreting pituitary adenoma; to investigate factors affecting and predicting the surgical remission in patient with growth hormone-secreting pituitary adenoma.METHOD: We retrospectively analyzed the data between Feb 2009 to Dec 2014 of all patients with acromegaly, who underwent transsphenoid surgery operated on by a single surgical group in our center. The patients were divided into two group according to the remission. We compared with the two groups of their biochemical and radiological results in order to find the difference in before and after the surgery and between two groups, and to see if the difference affects the remission. By using survival analysis and making Kaplan-Meier curves, we compared different factors affecting the surgical remission. The Cox proportional hasards model allowed us to determine factors who would predict the remission.RESULTS: There were 63 patients with GH-secreting pituitary adenoma operated on in our center between Feb 2009 and Dec 2014, 3 was eliminated since lack of information. The average age is 47.9 ± 11.2 years old, where 39 were females and 21 were males, and the male/female ratio is 1:1.86. The median follow-up time is 440.5 days during which 36 got remitted while other 24 did not. Biochemical remission was achieved in 60% of all patients based on our criteria. There was no difference in age and gender between the remission group and the non-remission group. The differences of statistical significance were found in remission rate between microadenoma and macroadenoma, between invasive adenoma and non-invasive adenoma, between preoperative GH>30μg/L group and GH≤30μg/L group, between intra-operative GH reduction ratio>40% group and reduction ratio≤40% group.K-M curves and Cox proportional hasards model shows that the size of adenoma, invasiveness of adenoma, pre-operative GH affect the post-operative remission. Intra-operative GH measurement and early post-operative GH may predict surgical remission.CONCLUSION: Higher pre-operative GH levels, larger adenoma size and invasion of the surrounded structure are associated with a lower probability of biochemical remission after surgery. Intra-operative GH reduction ratio may predict outcomes of the surgery. Early postoperative GH levels are highly predictive for outcome of surgery for GH-secreting pituitary adenoma patients.