Multi-Center, Multi-National Outcomes Following Endoscopic Endonasal Resection of Nonfunctional Pituitary Adenomas.

Objective: Nonfunctioning pituitary adenomas (NFPA) are common, benign lesions of the pituitary gland. The endoscopic endonasal approach (EEA) has improved their treatment. Large multi-center data across different healthcare systems on outcomes following EEA resection of NFPA are limited. We aimed to provide highly generalizable benchmark outcomes from an international, multi-center review of EEA for NFPA resection. Methods: Institution-level data on symptoms, tumor and intraoperative characteristics, complications, and long-term outcomes were obtained from four tertiary pituitary centers located in the United States (2), Italy (1), and Austria (1). Means and weighted averages were used to generate descriptive statistics of patient characteristics and outcomes. Results: A total of 1,097 patients who underwent EEA for NFPA were included (mean age: 55.3 years). Presenting symptoms included vision loss (55.2%) and headache (42.1%). The most common preoperative endocrinopathies were hyperprolactinemia (26%) and hypothyroidism (18%). The gross total resection rate was 66%. Patients presenting with headache and visual symptoms experienced improvement (81 and 89%, respectively). Common complications included delayed hyponatremia (7.5%), transient arginine vasopressin deficiency (AVP-D; 6.6%), cerebrospinal fluid leak (3.5%), new endocrinopathy (3.5%), and new cranial nerve palsy (0.8%). There were no instances of carotid artery injury. Stroke (0.4%) and death (0.1%) were exceedingly rare. During the mean follow-up of 30 months, <5% of patients underwent reoperation or radiation-based treatments. Conclusion: In this large, international series, EEA proved a safe and effective intervention that was generalizable across centers in the United States and Europe. Severe complications were rare, and significant improvements in headache and vision loss were noted in most patients.