Introduction: In the resection of pituitary adenomas or Rathke’s cleft cysts (RCC), the anterior pituitary gland is often partially or completely obstructing transsphenoidal access to the lesion. In such cases, a gland incision and/or partial gland resection may be required to obtain adequate tumor/cyst exposure. We investigated the frequency with which this technique was performed in our practice and determined the associated risk of post-operative hypopituitarism.

Methods: All patients who underwent endoscopic-assisted or fully endoscopic removal of a pituitary adenoma or RCC between January 2011 and January 2013 (minimum 3 month follow-up) and had a gland incision or resection were included. Pre- and post-operative pituitary hormonal status was evaluated.

Results: Of 137 operations, an anterior gland incision or resection was performed in 41 cases (30%) in 39 patients. In 25 cases a vertical gland incision was made. In 16 cases a partial gland resection was performed including 8 partial hemi-hypophysectomies and 8 resections of thinned/ attenuated anterior gland draped over a large macroadenoma. Diagnoses included 32 pituitary adenomas (12 endocrine-inactive, 11 Cushing’s, 7 prolactinomas, 2 acromegaly) and 9 RCCs. Of 33 patients with complete endocrine follow-up data, new permanent hypopituitarism occurred in 1 (3%) patient with a 3 cm macroadenoma who had partial gland resection; 2 patients experienced transient hyponatremia. Overall gland improvement occurred in 7/13 (54%) patients with pre-operative hypopituitarism, including 5 with resolution of 1 axis or of stalk-effect hyperprolactinemia and 2 with resolution of 2 or more axes.

Conclusions: Pituitary gland incisions and partial gland resections are generally well-tolerated and can be performed when necessary to gain access to pituitary adenomas or RCCs. This technique, performed in 30% of our cases, appears to minimize traction on the normal pituitary gland during removal of large tumors or cysts and facilitates better visualization of microadenomas embedded in the anterior gland.

Patient Care: We hope to prove that incisions and partial resections of the pituitary gland improve tumor or cyst visualization while minimzing traction on the normal gland and preserving postoperative gland function. Therefore this practice should be utilized when necessary in endonasal transsphenoidal approaches for pituitary adenomas or Rathkes Cleft Cysts.

Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the importance of performing a pituitary gland resection or incision during endonasal transsphenoidal removal of a pituitary adenoma or Rathke's Cleft Cyst and the associated low risk of postoperative gland dysfunction 2) Discuss in small groups the risk factors for postoperative hypopituitarism 3) Identify when a partial pituitary gland incision or resection is necessary during endonasal transsphenoidal surgery

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