Investigation of factors that contribute to the outcome of endoscopic transsphenoidal surgery as reviewed from our own cases

Abstract

In order to improve the treatment outcome of endoscopic transsphenoidal surgery (eTSS), it is important to identify the factors that contribute to the tumor resection rate and/or post-operative complications, and to devise a surgical strategy for each case. In the present study, we retrospectively evaluated our own experience of eTSS for primary pituitary adenoma (PA), and sought the factors that are related to patients’ surgical outcomes. Thirty-three cases of primary PA operated on by eTSS at our institution in a recent 5-year period were investigated. The patients’ data for age, sex, Knosp grade, operating time, sellar floor opening rate, tumor resection rate and post-operative complications were evaluated. The median rate of tumor resection was 91.3%, and the tumor resection rate demonstrated significant linear relationships with age (Z = −0.41, p = 0.02), sex (Z = −0.42, p = 0.01) and sellar floor opening rate (Z = 0.47, p = 0.01). A significant linear relationship was also found between sex and sellar floor opening rate (Z = −0.51, p < 0.01). However, post-operative cerebrospinal fluid (CSF) leakage occurred in 2 cases where the sellar floor was opened widely. We reviewed the details of these 2 cases in this article. The gender difference observed in this study results was thought to be due to the difference in size of the nostril; however, further verification is required. Although wide sellar floor opening can contribute positively to aggressive PA resection in eTSS, this may increase the risk of CSF leakage. If a case requires a higher resection rate, especially in functional PA invading the cavernous sinus, the surgeon should adopt and perform advanced techniques of sellar floor reconstruction according to those carried out in the expanded endonasal approach for the frontal skull base or clivus area.