Why Patients Undergo Endoscopic Endonasal Transsphenoidal Pituitary Adenoma Surgery: Characterization of a Large North American Patient Population

Background Pituitary tumors account for up to 15% of all intracranial tumors, 90% of which are adenomas. The surgical treatment of pituitary adenoma has evolved greatly over the decades since its inception insofar as the approaches to the sella and the expected surgical results and the resultant associated morbidity of surgery. To better understand the patient population and the surgical treatment that they receive, we conducted an institutional review for pituitary adenoma surgery done using the endoscopic endonasal transsphenoidal (EETS) approach.

Study Design Retrospective cohort, single institutional study.

Methods Institutional REB approval was attained for a retrospective review of all EETS cases for pituitary tumor resection between November 2009 and June 2016. Queries of the hospital database were completed by medical records personnel to identify cases of pituitary tumors resected using the EETS approach. Patient characteristics, tumor type, endocrine data, and operation characteristics were then extracted from medical records pertaining to patient baseline characteristics. Preoperative MRI images were reviewed and the SIPAP classification applied to the pituitary tumors. Postoperative results were extracted for the duration of the follow-up period available for each patient.

Results A total of 202 cases were identified, 57% of the cohort was male. The mean age of the cohort was 56 years old. During the study period, five different neurosurgeons performed EETS for patients with pituitary tumors. A mean of 30 pituitary adenoma cases were completed yearly. Functional tumors were present in 29% of the cohort. The most common functioning tumors in the cohort were GH and ACTH secreting tumors. 37% of patients underwent surgery due to vision loss from the adenoma. Complete excision was most common for functioning tumors (49%) in comparison to nonfunctioning tumors (26%). There were a total of eight postoperative CSF leaks (3.9%), with five cases requiring reoperation. There were no major vascular injuries. Nine patients developed bacterial sinusitis requiring antibiotic therapy in the immediate postoperative period. Hormone replacement with cortisol was required transiently in 80% of patients, with thyroid hormone replacement occurring in 40% of the cohort.

Conclusion From this large North American cohort, nearly 30% of operated pituitary tumors were functioning. More commonly, these tumors were completely resected compared with the nonfunctioning group. There was a low rate of major complication with the EETS approach. The most commonly replaced hormone following EETS surgery was cortisol and this was largely transient.

No conflict of interest has been declared by the author(s).