Transition From Microscopic to Endoscopic Transsphenoidal Surgery for Nonfunctional Pituitary Adenomas

OBJECTIVE: At our institution, a total of 320 patients were operated on between 2000 and 2010 for a newly diagnosed pituitary adenoma. In an attempt to improve quality of tumor resection, the transsphenoidal microscopic technique was replaced by the endoscopic technique in June 2008. This retrospective single center study compares the outcomes after microscopic (n = 144) and endoscopic (n = 41) tumor surgery of all patients operated on for a nonfunctional pituitary adenoma. METHODS: Tumor size and location, Knosp grade, prevalence of anterior hypopituitarism, diabetes insipidus, visual acuity/fields, complication rates, and operation time were compared between the groups. RESULTS: At the 3-month follow-up, hypopituitarism had improved in 7% of patients in the microscopic group and in 9% in the endoscopic group, and had further impaired in 13% and 9%, respectively. At the 3-month follow-up magnetic resonance imaging, a total tumor removal was achieved in 45% versus 56% of patients, respectively (P = not significant [NS]). Visual fields had normalized or improved in 90% versus 88% of patients, respectively (P = NS). Postoperative cerebrospinal fluid leak occurred in 3.5% versus 2.4% (P = NS), and diabetes insipidus (transient or permanent) in 7.6% versus 4.9% (P = NS) of cases, respectively. Larger tumor size (P < 0.0005) and endoscopic technique (P = 0.03) were independent predictors of increased mean operative time. CONCLUSIONS: Initial results with the endoscopic technique were statistically similar to those achieved with the microscopic technique. However, there was a trend toward improved outcomes and fewer complications in the endoscopic group.