Introduction: Giant pituitary adenomas (GPA) are defined as tumors > 40 mm in diameter and account for 5-14% of all pituitary adenomas. Despite advances in field of microsurgery, these adenomas still pose a great therapeutic challenge. An endoscopic endonasal approach is less invasive and increases the extent of resection. In this study, we analyzed our surgical results for 37 cases of GPA operated by endoscopic endonasal approach (EEA) and estimated the efficacy and complications in terms of tumor extension and type, and discuss the advantages and limitations of this technique.

Methods: This study is a retrospective analysis of 37 patients with pituitary adenomas > 40 mm treated by endoscopic endonasal skull base approach between 2009 and 2016. Neurological, visual, endocrinological and surgical outcomes were analyzed.

Results: Males comprised 75.7 % of study population with median age at presentation being 40 years. Non-functional tumours were the most commonly encountered (56.8 %) followed by Growth Hormone secreting tumors (21.6%) and Prolactinomas (8.1%). The average tumour volume was 32.38cc(Range: 12.1 – 90.8cc). Gross total excision was achieved in 15 cases(40.5%). Postoperative complications included transient DI in 9 cases (24,3 %), apoplexy in 5(13.5 %) and cerebrospinal fluid leak occurred in 12 patients (32.4 % ) all of whom were managed conservatively. Visual improvement occurred in 22 cases (59.5 %) while it remained same as pre-operative vision in the another 13 patients (35.13%). 11 patients (29.7 %) required long term hormonal replacement. There were 4 mortalities related to tumor volume, knosp grading, multi-compartmental extension of tumor, post-operative apoplexy in residual tumor and multiple co-morbidities.

Conclusions: Endoscopic endonasal skull base approach enables less invasive and safe removal of various extension types of giant pituitary adenomas with complications and results comparable to other transcranial and transsphenoidal approaches. Early visual improvement occurs due to adequate decompression of optic apparatus.

Patient Care: In this study, we analyzed our surgical results for 37 cases of giant pituitary adenomas operated by endoscopic endonasal approach (EEA) and estimated the efficacy and complications in terms of tumor extension and type, and discuss the advantages and limitations of this technique. This has resulted in complete switch in our departmental protocol for surgical treatment of giant pituitary adenomas from microscopic trans-sphenoidal to endoscopic endonasal trans-sphenoidal approach.

Learning Objectives: Giant Pituitary Adenomas (37 cases) operated by endoscopic endonasal approach (EEA): An endoscopic endonasal approach is less invasive and increases the extent of resection of various extension types of giant pituitary adenomas with complications and results comparable to other transcranial and transsphenoidal approaches. Early visual improvement occurs due to adequate decompression of optic apparatus.

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