Pituitary surgery in New Zealand: A single neurosurgeon case series of 1,224 operations

Pituitary neuroendocrine tumours (PitNETs) are among the most common tumours of the central nervous system, yet data regarding surgical outcomes is limited for New Zealand (NZ). This study presents a 23-year single-surgeon case series of pituitary surgery. A retrospective analysis of 1,224 pituitary operations performed between August 1999 and July 2023 was conducted. Patient demographics, tumour characteristics, complications, and long-term outcomes were analysed. Statistical analyses included univariate and multivariate models. Pituitary neuroendocrine tumours (PitNETs) accounted for 88 % of cases (n = 1,087), including 612 non-functioning, 175 GH-producing, and 112 ACTH-producing tumours. The complications of transsphenoidal surgery for PitNETs included postoperative cerebrospinal fluid (CSF) leaks (7.3 %), permanent diabetes insipidus (3.4 %), meningitis (2.4 %), and visual deterioration (1.2 %). Carotid injury, stroke, and death within 30 days each occurred in less than 1 % of cases. Among 554 non-functioning PitNETs with surveillance imaging, 20 % recurred after a median follow-up of 3.7 years (IQR 1.6-7.7), with 10 % requiring reoperation. Recurrence was detected in 60 % of cases by five years and 90 % by ten years, of those who recurred. Age was protective, with each additional year reducing risk (HR = 0.98, p = 0.005). Cavernous invasion strongly predicted recurrence (HR = 2.9, p < 0.001). No significant association between ethnicity and recurrence was observed, including among Māori and Pasifika patients. Surgical remission in acromegaly was achieved in 76 % of microadenomas (median follow-up: 4.8 years; IQR: 1.0-6.8) and 75 % of macroadenomas (median follow-up: 4.3 years; IQR: 1.5-8.5). In Cushing's disease, remission was achieved in 82 % of microadenomas (median follow-up: 3.1 years; IQR: 0.8-9.2) and 75 % of macroadenomas (median follow-up: 4.0 years; IQR: 0.6-8.7). These findings demonstrate postoperative outcomes, complication rates, hormonal improvement, and tumour control, comparable to international standards.