Role of pituitary stalk and gland radiological status on endocrine function and outcome after endoscopic transsphenoidal surgery for non-functioning pituitary adenomas

Purpose To investigate endocrine function changes after non-functioning pituitary adenomas (NFPA) transsphenoidal surgery and to search for predictors of hypopituitarism resolution and development. Methods We included 117 patients with NFPA who underwent endoscopic transsphenoidal surgery from 2005 to 2019 by two neurosurgeons. Twenty-one patients were excluded because of previous pituitary surgery or radiotherapy. We assessed symptoms at diagnosis, tumour volume, tumour removal, hormonal status at diagnosis, hormonal outcomes at 2- and 12-month follow-up, and complications. Pituitary stalk and gland MRI status (visible or not) were included, and it theirs association to hormonal function was studied for the first time, to our knowledge. Results Pituitary gland visualization was more frequent in those patients who showed a smaller number of axes affected at 12 months (p = 0.011). Pituitary stalk status showed no association to hormonal function. The hormonal normalization rate at 12 months was 13%. The endocrine improvement rate at 12 months was 16.7%. Worsening of hormonal function occurred in 19.8% of patients. Younger age was associated to hormonal improvement (p = 0.004). Higher preoperative tumour volume (p = 0.015) and absence of gross total resection (GTR) (p = 0.049) were associated with worsening in at least one hormonal axis after surgery. Conclusions Pituitary gland visibility was higher in those patients who showed better hormonal outcomes. Assessment of initial hormonal function and outcome after surgery regarding pituitary stalk status showed no significant association. Higher preoperative tumour volumes and absence of GTR were associated to postoperative endocrine function worsening, while younger age was associated to its improvement.