Refined Endoscopic Extracapsular Resection Technique for Pituitary Adenomas With Suprasellar Extension: A Retrospective Analysis of 259 Cases

BACKGROUND AND OBJECTIVES: Extracapsular resection is effective for functioning pituitary adenomas, but its role in tumors with suprasellar extension remains unclear. The aim of this study was to evaluate surgical outcomes of a refined endoscopic transnasal technique for nonfunctioning pituitary adenomas with suprasellar extension, focusing on pseudocapsule-based extracapsular resection. METHODS: We retrospectively analyzed 259 patients with tumors ≥20 mm and ≥1-year follow-up (2007-2023). Factors associated with complete pseudocapsular resection and surgical outcomes were evaluated using unadjusted and multivariable logistic regression analyses stratified by surgical period. RESULTS: A pseudocapsule was identified in 52.5% of cases, and complete resection was achieved in 34.4%. Total resection was achieved in 73.7%, with most residual tumors in the cavernous sinus. Complete pseudocapsular resection was associated with smaller tumor size, reduced intraoperative cerebrospinal fluid leakage, lower residual tumor rates, and fewer postoperative hemorrhages and complications in unadjusted analyses.In multivariable analyses, these associations were significant in the early period but not in the later period, whereas reduced overall complications remained significant across both periods. Tumor regrowth occurred in 22 patients and was controlled with stereotactic radiotherapy. Tumor size-but not suprasellar extension-was associated with complete pseudocapsular resection. CONCLUSION: Complete pseudocapsular resection is associated with improved outcomes, particularly during earlier phases of surgical experience, although its relative impact may decrease with increasing surgical proficiency. Careful identification and resection of the pseudocapsule should be pursued when feasible.