Surgical Results of Pure Endoscopic Endonasal Transsphenoidal Surgery for 331 Pituitary Adenomas: A 15-Year Experience from a Single Institution

Background The aim of this study is to report the results of pure endoscopic endonasal transsphenoidal surgery (EETSS) for pituitary adenomas (PAs) and to evaluate the efficacy and safety of this procedure. In addition, we tried to determine the predicting factors for progression of PAs. Methods We reviewed the medical records of 331 consecutive patients who underwent pure EETSS of newly diagnosed PAs between April 1998 and December 2014. Demographic, endocrinologic, and radiologic features and their outcomes, complications, and hospital stay durations were retrospectively assessed in these patients. Results There were 157 (47.4%) nonfunctioning adenomas and 174 (52.6%) hormone-secreting adenomas. Fifty-one (15.4%) complications were present in 39 patients postoperatively. The frequent complications were temporary and permanent diabetes insipidus (14 and 3 cases, respectively), syndrome of inappropriate antidiuretic hormone secretion (9 cases), and cerebrospinal fluid leaks (6 cases). There was only 1 death (0.3%) related to the procedure in this series. The patient's age (P = 0.047), the tumor size (P = 0.003), and the parasellar growth (P <0.001) were associated with the occurrence of complications on multivariate analysis. Progression occurred in 92 (27.8%) patients and the mean time-to-progression was 23.7 months (range, 3.7–52.4 months) after a mean follow-up period of 68.5 months. In the multivariate analysis, the tumor size (P = 0.021), the extent of surgery (P = 0.012), the Knosp classification (P = 0.002), and the MIB-1 index (P = 0.019) were associated with progression-free survival. The mean duration of hospitalization was 4.4 (±1.6) days. Conclusions The pure EETSS of PA provides acceptable and reasonable results representing a safe alternative procedure to the traditional transsphenoidal microscopic approach.