The outcomes of surgical treatment via transsphenoidal approach for patients with nonfunctioning pituitary adenoma: a single institution's experience.

Background: Nonfunctioning pituitary adenoma is a primary benign brain neoplasm and the transsphenoidal approach is known for a safe and effective first-line surgical treatment for pituitary tumours. The aim of this study was to retrospectively analyse the outcomes of the transsphenoidal approach for nonfunctioning pituitary adenomas treated at a single institute.

Methods: A total of 181 patients who underwent transsphenoidal approach with nonfunctioning pituitary adenoma at a single institute from March 1998 to November 2018 were included in this study. Ninety-six (53.0%) men and 85 (47.0%) women aged 21-79 years were included. The median outpatient follow-up duration was 58 months, and the median magnetic resonance imaging follow-up duration was 54 months. We assessed the surgical and clinical outcomes, complications, hormonal outcomes and recurrence tendency.

Results: The overall total resection rate of a transsphenoidal approach for nonfunctioning pituitary adenoma was 84.0%. Visual impairment was improved after surgery in 115 (93.5%) of 123 patients. Of the 80 patients who complained of preoperative endocrine dysfunction, 62 (77.5%) patients recovered normal postoperative endocrine function. Diabetes insipidus, which occurred in 22 (12.2%) patients, was the most common complication. A total of 21 (11.6%) patients showed recurrence on average 57.6 months after surgery. The average recurrence period after surgery was 96.3 months in the total resection group of 6 patients and 42.1 months in the subtotal resection group of 15 patients. In multivariate analysis, the extent of resection was identified as a significant predictor of tumour recurrence with a hazard ratio of 6.093 and a -value of 0.002.

Conclusions: It is meaningful to report long-term surgical results within a single institution, and through this, it was reconfirmed that transsphenoidal approach is an effective and safe treatment for nonfunctioning pituitary adenoma. Long-term follow-up is required due to the possibility of recurrence. In addition, performing total resection during surgery helps to lower the risk of recurrence.KEY MESSAGESTranssphenoidal approach is an effective and safe treatment modality for pituitary adenoma.Complete resection is a significant predictor for the recurrence of pituitary adenomaLong-term follow-up is necessary for the treatment of nonfunctioning pituitary adenomas.