Endocrine Abstracts

Background & Aims: The aims of transsphenoidal surgery (restoration/preservation of vision and amelioration of hormonal excess) are balanced against the risk of inducing new post-operative pituitary deficits. This study aims to assess the rate of new anterior hormonal deficits following transsphenoidal pituitary adenoma surgery in our centre and to assess whether the visibility of normal pituitary gland on pre-operative imaging predicts this.

Methods: Patients undergoing first transsphenoidal surgery for a pituitary adenoma between 2012 and 2016 were identified. Pre-operative imaging was reviewed and the presence or absence of visible normal pituitary gland on MRI noted. Biochemical testing/medications pre-operatively and six weeks post-operatively were reviewed.

Results: Full data were available for 132 patients [71 male, 61 female, ages 14-87 yr (median 53 yr); 100 macroadenomas, 32 microadenomas; 61 non-functioning, 71 functioning (38 acromegaly, 13 Cushing’s, 5 thyrotropinoma, 14 prolactinoma, 1 gonadotrophinoma)]. Of these, 37 had new deficits post-operatively (22 ACTH alone, 9 ACTH plus other hormones, 7 one or more other hormones without ACTH). The visibility of normal pituitary pre-operatively did not predict the development of post-operative axis deficits (P=1.000, Fisher’s exact test). An interim analysis in 2014 noted that of 25 patients undergoing surgery in 2012, 10 had ACTH deficiency at six weeks post-op but at 4 months, 5 of these had recovered this axis (2 persisting ACTH-deficiency, 3 data at 4 months incomplete). Our routine practice in 2012 was to discharge all patients on full replacement hydrocortisone (10/5/5 mg/day). Since 2015 our practice has been to personalise hydrocortisone on discharge based on post-operative 9am cortisol (2^nd or 3^rd day post-op). In 2016, 4/30 patients had ACTH-deficiency at 6 weeks post-op.

Conclusions: Discharge hydrocortisone dosing after transsphenoidal surgery should reflect individual patient requirements to avoid (reversible) HPA axis suppression. The ability to visualise normal pituitary on pre-operative MRI does not predict post-operative hypopituitarism.