Endocrine Abstracts

Transphenoidal surgery is an effective treatment option in patients with pituitary tumours associated with compression of the optic chiasm or hormone hypersecretion. Surgery carries with it a risk of the development of new pituitary hormone deficits but also the potential for recovery of existing pituitary hormone deficits. We have examined data concerning pituitary function in 80 patients who underwent endoscopic transphenoidal pituitary surgery at Royal Preston Hospital.

The majority of patients had non-functioning pituitary tumours (44), 25 were GH secreting, 2 ACTH secreting, 1 FSHoma, 1 prolactinoma, 1 gonadotrophin secreting adenoma and 6 craniopharyngiomas. Visual field defects were present in 47. Preoperative assessment revealed ACTH deficiency in 32%, TSH deficiency in 33%, and gonadotrophin deficiency in 57%. 1 patient had diabetes insipidus pre-operatively and testing for GH deficiency was not routinely done prior to surgery. The proportion developing new post-operative hormone deficits in those with a normal axis before surgery was 36%, 37% and 12% for ACTH, TSH and gonadotrophins respectively, whilst recovery of hormone production was observed in 18.2%, 3.8% and 9.5% of those with preoperative ACTH, TSH or gonadotrophin deficiency. In addition new persistent postoperative diabetes insipidus was seen in 12.5% of patients. GH stimulation tests were performed in symptomatic post-operative patients and confirmed severe GH deficiency in 16 of 25. Of the 47 patients with visual field defects, information on postoperative visual fields was available in 44. Of these patients 37 (84%) improved, 4 (9%) remained stable and 3 (7%) deteriorated.

Baseline tumour size significantly correlated with the likelihood of pre-operative hormone deficiencies (TSH P=0.04, ACTH P=0.0005, gonadotrophins P=0.05), visual field defects at presentation (P=0.001) and the risk of developing new postoperative ACTH deficiency (P=0.007).

These findings highlight the importance of postoperative hormone assessment and are useful when counseling patients regarding the risks of surgery.