Efficacy and complications of endoscopic skull base surgery for giant pituitary adenomas

Abstract Objective Treatment of giant pituitary adenomas is challenging. Endoscopic endonasal skull base surgery (EES) was estimated the surgical results and complication for giant pituitary adenomas. Methods Thirty-four pituitary adenomas larger than 40 mm treated by EES between 2002 and 2015 were studied. Removal rates, symptoms, and complications were analyzed by direction of tumor extension. Results Average tumor size was 45.5 mm. Near-total resection (NTR) was achieved in 16 of 34 (47.1%) cases. NTR was observed significantly more in anterior extension types and round tumor in superior extension type, however, not achieved in multiple extension cases. The average residual amount in 18 partial removal cases was 30.2% of preoperative volume, with no significant difference between groups. Eight cases showed regrowth after partial removal but controlled tumor growth and improved symptoms by repeated surgery or stereotactic radiotherapy. Postoperative improvement of visual field deficits was achieved in 23 of 25 (92.0%) cases. Postoperative complications included visual deterioration in 1, cerebrospinal fluid leakage in 2, and cerebral infarction due to perforator injury in 2 and one case of multiple extension type had symptomatic intratumoral hemorrhage. Conclusions EES enabled less invasive and safer removal of various extension types of giant pituitary adenomas. Preservation of visual function is essential. Two-stage surgery or partial resection with additional treatments is possible to be carried out without complications if a sufficient amount of resection is performed. However, in cases with tumors that may be expected the insufficient resection, alternative treatment including combined-simultaneous resection should be considered.