Endoscopic transsphenoidal surgery reduces the need for re-operation compared to the microscopic approach in pituitary macroadenomas

Introduction: Pituitary surgery has shifted in recent years from microscopic surgery(MS) to endoscopic endonasal surgery (EES). However, the comparative long-term outcome of these surgical approaches, including the need for subsequent re-operation has never been reported. We present our experience in a high-volume referral center experienced in both endoscopic and microscopic approaches to compare the need for re-operation after initial resection of non-functioning pituitary macroadenomas using these surgical approaches. Methods: 684 patients (398 with NF adenomas) underwent trans-sphenoidal pituitary surgery in our institution between 2006 and 2017. Complete follow-up (mean 72 months, minimum two years) was available in 87 newly diagnosed patients with non-functioning pituitary macroadenomas (NFPMA; 48-microscopic and 39-endoscopic). The EES approach has been used almost exclusively since 2012. The need for repeat operation for tumor resection during the follow-up period was assessed as the primary end-point of the study. Extracted data included various demographic and clinical parameters, radiographic findings as well as the extent of resection (EOR). Results: The EOR was similar for both groups, with a trend towards better EOR in the EES group. The rate of surgical complications was also similar for both groups. There was a strong trend towards lower need for re-operation in the EES group compared to the MS group (12.8% vs. 29.2%, p = 0.056). In a multivariate analysis, only EOR and Knosp grade were independently associated with the need for re-operation surgery. Conclusion: Our data indicate that EES in NFPMA tends to be associated with a lower need for re-operation compared to the MS approach, with a similar rate of EOR and complications.