Volumetry in the Assessment of Pituitary Adenoma Resection: Endoscopy versus Microscopy.

Background  Assessment of the extent of resection after surgical resection of pituitary adenomas is most commonly reported in terms of the presence or absence of residual tumor. A quantitative comparison of volumetric resection between endonasal endoscopy (EE) and microsurgery (MS) has rarely been done. Methods  A retrospective analysis was performed on a consecutive series of 154 patients with pituitary adenomas treated by the same surgeon at a single institution. We employed volumetric analysis pre- and postoperatively on two cohorts of pituitary adenoma patients treated through MS ( n  = 37) versus EE approach ( n  = 117). Results  Volumetric analysis revealed a higher incidence of complete resection (64.4 vs. 56.8%) and mean volume reduction in the EE cohort (92.7 vs. 88.4%), although not significant. Recurrence rates were significantly lower in the EE group (7.7% vs 24.3%, p  = 0.015). Subgroup analysis identified that patients with preoperative tumor volumes >1 mL were less likely to recur through EE (7.8 vs. MS: 29.6%; p  = 0.0063). A higher incidence of complete resection was also noted in patients with favorable Knosp grades (0-1) (EE: 87.8 vs. MS: 63.2%; p  = 0.036). Postoperative complication rates were not significantly different between both techniques. Conclusion  Both microscopy and endoscopy are well-tolerated, effective approaches in the treatment of pituitary adenomas. Our series demonstrated that EE may be superior to MS in preventing tumor recurrence and achieving a complete resection in certain subsets of patients. EE provides a slight advantage in tumor control outcomes that may justify the paradigm shift to pure endoscopy at our center.