Predictive Factors for Diabetes Insipidus and Syndrome of Inappropriate Secretion of Antidiuretic Hormone After Transsphenoidal Surgery for Pituitary Adenoma.

Objective The objective of this study is to determine preoperative predictors of diabetes insipidus (DI) and syndrome of inappropriate secretion of antidiuretic hormone (SIADH) after transsphenoidal surgery (TSS) for pituitary adenomas. DI and SIADH are common complications associated with TSS. Methods This small unicentric retrospective study was conducted in a tertiary referral hospital in Saudi Arabia. The study enrolled 42 patients. We reviewed the medical records of all patients who underwent surgical resection of pituitary adenoma at our hospital between January 2010 and December 2022. The results of urine and serum analyses were collected to establish a diagnosis. Pre- and post-surgery sodium differences were categorized by the pre-surgery value to calculate the percent change in sodium levels. The tumor function was confirmed using histopathology, and radiological reports were reviewed for the size, location, extent, invasiveness of the tumor, and cerebrospinal fluid (CSF) leaks. Results Among the 42 patients included, seven (16.7%) had DI and two (4.8%) had SIADH. Two-thirds underwent resection using the microscopic approach, and the remaining patients underwent endonasal TSS. Approximately 43% of patients had functioning pituitary adenomas, with prolactin-secreting adenomas being the most common (21.4%). Three-quarters of the tumors were macroadenomas. No significant between-group differences were observed in the length of hospital stay, preoperative sodium levels, and percentage change in serum sodium (P>.05). Smoking and chronic hypertension were not associated with DI or SIADH. The number of patients with panhypopituitarism (P<.01) or hypothyroidism (P<.01) was significantly different between the DI and no DI groups. However, no factor significantly predicted the development of DI. No significant differences were observed between the SIADH and non-SIADH groups. Conclusion The risk of DI increases in patients who develop panhypopituitarism, including central hypothyroidism after surgery. However, no factor reliably predicts the development of DI or SIADH after TSS.