Brain injury biomarkers and intraoperative hypotension: associations with pituitary hormone deficiency following transsphenoidal endoscopic surgery for non-functioning pituitary adenomas

Purpose Factors related to the development of new pituitary hormone deficiencies following transsphenoidal surgery for non-functioning pituitary adenomas are multifactorial and remain poorly understood. We explored associations with brain injury biomarkers and investigated intraoperative hypotension (IOH) as a potential mediator. Methods This prospective study included 100 patients undergoing endoscopic transsphenoidal surgery. Two individual outcomes at 12-months postsurgery were analysed: new anterior pituitary hormone deficiency (APH-D) and new arginine vasopressin deficiency (AVP-D). Plasma concentrations of glial fibrillary acidic protein (GFAP), neurofilament light chain (NfL), and tau were measured preoperatively and on postoperative days 1 and 5. IOH was assessed using two definitions: duration below an absolute MAP threshold of 65 mmHg and duration below a relative threshold of 20% below preoperative MAP. Associations between new deficiency and biomarkers were assessed using mixed-effects models, and associations with IOH were evaluated using the Mann–Whitney U test. Results Elevated postoperative GFAP, NfL, and tau were associated with new APH-D, with GFAP also linked to new AVP-D. Patients who experienced new APH-D demonstrated longer durations of relative IOH (median [IQR] 155 min [54–216] vs. 82 min [20–154]; p = 0.03). There was no difference in relative or absolute IOH for those with new AVP-D. Conclusion Elevated postoperative plasma GFAP, NfL, and tau might indicate increased risk of long-term postoperative pituitary hormone deficiency. Relative IOH may also contribute to these deficiencies.