Outcome of acromegalic patients undergoing endoscopic endonasal surgery: collaborative French and Italian cohort, a 25-year experience.

It has been demonstrated that high expertise is crucial for pituitary surgery. Due to the low incidence of acromegaly, large data reporting the outcome of endoscopic surgery are limited. The objective was to evaluate the outcomes of acromegalic patients undergoing endoscopic surgery. This retrospective study included 822 consecutive acromegalic patients treated by endoscopic endonasal surgery by two expert French and Italian neurosurgical teams from 1998 to 2022. The primary outcome was postoperative endocrine remission. The secondary outcome was operative morbidity, including surgical complications and new endocrine deficits. Preoperative predictive factors of persistent postoperative hypersecretion were calculated. Mean follow-up was 46.3 months. The overall remission rate was 63%. Long-term remission was achieved in 202/230 (88%) enclosed microadenomas, 316/452 (70%) macroadenomas without obvious cavernous sinus invasion, and 3/140 (2%) obvious invasive tumors. Hematoma, nerve palsy, cerebrospinal fluid leak, meningitis and epistaxis occurred in 0.1%, 0.1%, 1%, 0.6% and 1.1% respectively. New anterior pituitary deficits and diabetes insipidus occurred in 25/822 (3%) and 30/822 (3.6%) of patients respectively. Age, obvious cavernous sinus invasion, and larger diameter were predictive of persistent hypersecretion in multivariate analysis. Recurrence of somatotroph hypersecretion occurred in 19/540 (4%) patients with early remission, with a mean time of 37.5 months. Endoscopic pituitary surgery is effective and safe for acromegaly, provided that patients are treated in tertiary reference centers. Remission rate is high in microadenomas. If normalized somatotroph axis is achieved after surgery, long-term remission can be expected in most patients.