Intraoperative cerebrospinal fluid leak graded by Esposito grade is a predictor for diabetes insipidus after endoscopic endonasal pituitary adenoma resection.

Abstract Background Diabetes insipidus (DI) is a well-known complication of transsphenoidal surgery (TSS). However, the risk factors for DI remain controversial. Methods We conducted a retrospective study of the patients who underwent endoscopic TSS for pituitary adenoma at our institution during a 5-year period. The patients were divided into a DI group and a non-DI group. Logistic regression analyses were used to identify risk factors for postoperative DI. In subgroup analysis, the DI group was divided into transient-DI and permanent-DI groups and the perioperative factors were compared between groups. Results Among 101 patients, 58 patients were classified as non-DI (57.4%) and 43 patients as DI (42.6%) group. Permanent DI occurred in seven patients （6.9%）. In the univariate analyses, statistically significant risk factors were suprasellar extension, tumor functionality and intraoperative cerebrospinal fluid (CSF) leaks by Esposito grade. In the multivariate logistic regression analysis, Esposito grade was the only statistically significant risk factor (P=0.015). The frequency of DI increased as the Esposito grade increased (P=0.0002 for the trend). In subgroup analysis, postoperative nadir sodium concentration was lower in the permanent-DI group (128.1±2.78 mmol/L) than in the transient-DI group (135±1.22 mmol/L) (P=0.035) and the optimal cut-off value was 124.5 mmol/L, with a sensitivity of 57.1% and a specificity of 91.7% (Area Under the Curve=0.76, P=0.034). Conclusions Intraoperative CSF leak by Esposito grade is associated with postoperative DI. These data can be applied to help identify high-risk patients who need more-aggressive follow-up and fluid management.