Correlation of Pituitary Descent and Diabetes Insipidus Following Transsphenoidal Pituitary Adenoma Resection

Introduction: Pituitary adenomas (PAs) are a common type of neoplasm arising from the pituitary gland. Endoscopic transsphenoidal surgery remains the technique of choice for resection of these tumors; however, major complications include cerebrospinal fluid leak, infections, hypopituitarism, carotid artery injury, and central diabetes insipidus (DI) among others. Postoperative DI is most often transient and observed in 1.6 to 34% of patients, while permanent DI has been reported in 0 to 2.7% of patients. Incidence of postoperative DI has been correlated with an intraoperative cerebrospinal fluid leak, Cushing's disease, decreased tumor size, and changes in serum sodium. The proposed mechanism was the transduction of traction forces exerted by the surgeon on the descended diaphragma sellae and through the pituitary stalk.

Methods: This study reports a cohort of 30 postoperative DI patients following transsphenoidal resection of a pituitary adenoma in a single neurosurgical institution between 2010 and 2020. We also report a matched cohort of 30 patients who did not develop DI postoperatively, matched by tumor volume. We quantified the tension on the pituitary stalk by calculating PDI (pituitary descent interval) by comparing pre- and postoperative position of the pituitary gland and using Pythagoras’ formula where PDI = √(CC² + AP²) with CC (craniocaudal) and AP (anterior-posterior) representing measurements of pituitary translation in respective directions after resection.

Results: We found significant difference with respect to pituitary descent between the groups in the craniocaudal (23.0 vs. 16.3 mm, p = 0.0015) and anteroposterior (2.4 vs. 1.5 mm, p = 0.0168) directions, but no difference in lateral translation (2.5 vs. 2.9 mm, p = 0.1811) (Table 2). There was statistically significant difference in PDI between the groups (23.2 vs. 16.6 mm, p = 0.0017).

Conclusions: We were able to quantify pituitary descent and subsequent tension on the pituitary stalk, while also associating it with development of postoperative diabetes insipidus after pituitary adenoma resection. Analyzing preoperative images for patients with tumors that have displaced their normal gland posteriorly and superiorly would help identifying a high-risk group for DI, and has significant implications for optimizing their perioperative care.

 

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No conflict of interest has been declared by the author(s).

Publication History

Article published online:
01 February 2023