Analysis of early postoperative risk factors for hypopituitarism after endoscopic endonasal transsphenoidal surgery for pituitary neuroendocrine tumors

Pituitary neuroendocrine tumors (PitNETs) are commonly managed with endoscopic endonasal transsphenoidal surgery (EETS), but early postoperative hypopituitarism remains a clinically important complication. This retrospective cohort study analyzed early postoperative risk factors for hypopituitarism in 124 patients with PitNETs who underwent EETS at a single center between January 2022 and December 2024. Endocrine status was assessed preoperatively, during the immediate postoperative period before discharge (postoperative days 3–7), and at scheduled outpatient reassessments at 1 and 3 months after surgery; the mean interval from surgery to endpoint endocrine assessment was 3.2 ± 0.6 months. Patients were categorized into a hypopituitarism group (n = 38) and a non-hypopituitarism group (n = 86) based on postoperative endocrine evaluation across the hypothalamic–pituitary–adrenal, thyroid, gonadal, and growth hormone axes. Demographic, radiologic, perioperative, and endocrine data were collected, and univariate and multivariate logistic regression analyses were performed. Patients who developed hypopituitarism were older and had larger tumors, higher Knosp grades, more frequent suprasellar extension, longer operation times, greater intraoperative blood loss, more intraoperative cerebrospinal fluid leakage, and lower rates of gross total resection. In the multivariate model, maximum tumor diameter (adjusted odds ratio [aOR] per 10-mm increase = 2.02, 95% confidence interval [CI]: 1.09–3.74) and Knosp grade 3–4 (aOR = 2.37, 95% CI: 1.03–5.46) were identified as independent risk factors for early postoperative hypopituitarism, whereas gross total resection was independently associated with a reduced risk (aOR = 0.39, 95% CI: 0.16–0.96). These findings indicate that tumor anatomy and extent of resection are key determinants of early endocrine outcomes after EETS and should be incorporated into preoperative risk stratification and postoperative endocrine surveillance; however, they should not be extrapolated to long-term pituitary functional recovery or deterioration without further follow-up.