Extra-pseudocapsule dissection technique in endoscopic endonasal transsphenoidal surgery for pituitary adenomas

Objective To investigate the significance of the concept of the pseudocapsule-based extra-capsular dissection technique in endoscopic transsphenoidal surgery for pituitary adenomas. Methods We performed a retrospective analysis on clinical data of 287 patients with pituitary adenomas who underwent endoscopic endonasal transsphenoidal surgeries at Neurosurgery Department of Zhongshan Hospital, Fudan University from October 2011 to December 2015. Patients were divided into two groups: pseudocapsule-based extra-capsular dissection group (157 cases) and intra-capsular resection group (130 cases). We compared their surgical and endocrinological outcomes and complications. Results The total resection rate in pseudocapsule-based extra-capsular dissection group was 89.8% (141/157) while that in intra-capsular resection group was 81.5% (106/130) (P=0.044). Furthermore, the recurrence rates in the extra-capsular and intra-capsular resection groups were 1.9% (3/157) and 6.9% (9/130), respectively (P= 0.035). Besides, with the application of extra-capsular dissection technique, the remission rate of functional adenoma in terms of biochemical parameters increased [56.5% (26/46) vs. 86.2% (50/58), P=0.001]. In addition, there was no difference in the rate of hypopituitarism, CSF leakage, intracranial infection or temporary polyuria (P>0.05). Conclusions The application of pseudocapsule-based dissection technique in endoscopic transsphenoidal surgery for pituitary adenomas could lead to a high rate of gross total tumor resection and endocrinological remission. Extra-pseudocapsular resection does not seem to cause additional postoperative complications. Key words: Pituitary neoplasms; Neuroendoscopy; Extra-pseudocapsule dissection technique; Endonasal transsphenoidal approach