The Importance of Long-Term Follow-up after Endoscopic Pituitary Surgery: Durability of Results and Tumor Recurrence

Introduction: Endoscopic transsphenoidal surgery (ETS) has become the preferred surgical approach for resection of pituitary adenomas in most centers. This technique has a series of advantages such as improved visualization and maneuverability when compared with microscopic transsphenoidal approach. However, long-term results are still scarce. Ten years ago, we published our initial series with short-term results. This project aims to revisit the results of that series, assessing now the long-term results regarding radiological recurrence of pituitary adenomas.

Methods: Retrospective analysis of consecutive, endoscopically managed pituitary adenomas in a single center from 2004 to 2007. Only patients with >5 years of follow-up (FU) were included in this study.

Results: A total of 98 patients matched the inclusion criteria for this study. The median follow-up period was 144 months. Nonfunctioning adenoma was the most common subtype (n = 66, 67.3%), followed by GH-secreting tumors (n = 19, 19.4%), ACTH-secreting tumors (n = 7, 7.1%), prolactinomas (n = 4, 4.1%), and TSH-secreting adenomas (n = 2, 2%). Age ranges from 23 to 82 years, with median age of 53 years. Preoperative visual deficits were observed in 46 patients (46.9%) and hormonal deficits were identified in 31% of cases. 22.4% of patients had undergone a previous pituitary adenomas resection prior to treatment in our center. Surgery achieved gross total resection (GTR) and near-total resection in 86 cases (85%; 50 and 35%, respectively). A total of 37 cases had recurrences during FU (mean recurrence free survival: 80 months). Recurrences were observed in 32% of patients who had had GTR, with mean RFS of 87.25 months, while recurrences were observed in 41.9% of patients who underwent near-total or partial resection (mean RFS = 69.22 months). Most recurrences occurred after 5 years of FU (23 cases <63% of all recurrences) and only four cases had recurrences in the first 2 years after surgery. Surgery and/or radiation were done for management of recurrences in 29/37 cases. Cavernous sinus invasion and cases that had undergone previous surgery were significantly associated with shorter RFS, among which recurrent case was most significantly associated in multivariate analysis (p = 0.05).

Conclusion: Long-term FU analysis demonstrates that progression/recurrence of previously resected adenomas is observed in a significant number of patients, especially in those in whom GTR was not achieved. Short-term FU may shadow real tumor control rates achieved after ETS and therefore, long-term FU should be pursued in all cases.