Endonasal Endoscopic Surgery for Macroadenomas: New Understanding of Pseudocapsules
Abstract PurposeExtracapsular resection of pituitary microadenomas has been widely reported, but only a few studies have carried out further investigations in macroadenomas, especially using the endonasal endoscopic approach. The authors of this study combined not only the interoperative characteristics of pituitary adenomas and pseudocapsules but also the surgical technique, outcomes and complications in macroadenomas to investigate the pseudocapsule.MethodsIn total, 143 consecutive patients with pituitary adenomas (maximum diameter 15 - 40 mm) who underwent endoscopic endonasal-transsphenoidal surgery between January 1, 2017, and August 1, 2019, were included in the study. ResultsAmong 143 patients, 48 patients had an intact pseudocapsule, 56 patients possessed an incomplete pseudocapsule and the remaining 38 patients had no pseudocapsule. A white and thick pseudocapsule was more frequent (p=0.016) in fibrous adenomas, but tumor fibrosis (p=0.004) and adenoma apoplexy (p<0.001) were the factors that predicted the pseudocapsular integrity and hindered en bloc extracapsular resection according to a logistic regression analysis. In addition, the adenoma size (p=0.185) did not influence pseudocapsular integrity. Partial capsulectomy for macroadenomas did not show a significant advantage over piecemeal resection in gross total tumor resection (GTR) or biochemical remission (p=0.731 and p=0.685, respectively), but GTR in whole capsular resection was 100%. Additionally, this resection method had a higher risk of intraoperative cerebrospinal fluid leakage (p=0.010) and a lower incidence of new hormone deficit (p=0.043) than piecemeal resection.ConclusionsThe pseudocapsule widely exists in pituitary macroadenomas and extracapsular resection can improve GTR and hormone remission rate and reduce the occurrence of postoperative pituitary dysfunction in short-time.