The impact of endoscopic transsphenoidal pituitary adenoma surgery on endocrine function: a single-centre study

Introduction The outcome for pituitary endocrine function following endoscopic transsphenoidal surgery remains unclear. This study aims to evaluate endocrine outcomes following endoscopic surgery in order to provide a benchmark to assist in the counselling of patients perioperatively. Methods A prospectively held pituitary database was retrospectively analysed for all adult pituitary adenoma patients undergoing endoscopic surgery from May 2011 to May 2017. All operations were performed by a single neurosurgeon at a regional centre for pituitary surgery. Functioning and non-functioning adenomas were included. Hormonal status was assessed at most recent follow-up. Results One hundred forty-five patients (69 M, 76 F) were included in the study with a median age of 52 years. Median follow-up was 52 months. Eighty-eight patients (61%) were not taking any hormone replacement medications, whilst 57 patients (39%) required hormone replacement therapy (HRT) preoperatively. Preoperatively, 29 patients (20%) had hypothalamo-pituitary-adrenal (HPA) axis dysfunction, 39 patients (27%) had thyroid axis dysfunction, 11 males (16%) and 7 females (9%) had gonadal axis dysfunction, and one patient had preoperative diabetes insipidus. Postoperatively, 26 patients (18%) had a new deficiency in pituitary function, whilst 6 patients (11%) were able to cease HRT. Nineteen patients (13%) had new HPA axis deterioration, 12 (8%) had new thyroid axis dysfunction, 8 males (11%) and 4 females (5%) had gonadal axis deterioration, and 6 patients (4%) had new diabetes insipidus (DI). Conclusions The ability to restore pituitary function following endoscopic surgery remains limited, whilst new deficits still occur. It is essential that patients are counselled accordingly as hormonal replacement therapy can have a significant impact on quality of life. Larger longer-term collaborative studies of endocrine outcome in endoscopic pituitary surgery are needed.