Exploring factors behind Arginine-Vasopressine deficiency in endoscopic endonasal surgery for PitNET: a single-center analysis of 349 patients.

Arginine-Vasopressine deficiency (AVP-D), formerly known as Central Diabetes Insipidus, is a well-known complication in surgery for sellar/parasellar masses. Although less frequent in endoscopic series than transcranial and microscopic transsphenoidal ones, AVP-D has been variably related to different factors. Focusing the work on pituitary Neuroendocrine Tumors (PitNET), all patients who were treated endoscopically at a single centre were retrospectively reviewed to analyze the occurrence of this complication. Patient's characteristics, radiological information, and operative data were collected for patients who underwent surgery for PitNET at the same Institution by a single surgeon in the period 2016-2022. AVP-D was diagnosed in the presence of new-onset hypotonic polyuria with or without hypernatremia and was defined persistent if required a treatment with desmopressine/DDAVP for more than 6 months. Out of 349 patients (mean age at surgery 57.5 years old) 44 (12.6%) developed AVP-D (25 transient and 19 permanent). Younger age, the presence of an intraoperative CSF leak, the maximum diameter of the lesion, its suprasellar extension (considering the presence of a visual deficit), consistency of the lesion (distinguishing 4 classes, soft, soft-fibrous, fibrous and fibrous-firm), the extent of resection and the functioning status showed some relationship at univariate analysis (p < 0.05) with this complication. Larger diameter and longer operative time were seen more frequently in permanent AVP-D. A more solid intraoperative consistency with the presence of adherences (class 4 vs. class 1, OR 11.14, 95%CI 1.20-103.4) and the appearance of an intraoperative CSF-leak (OR 8.27, 95%CI 3.92-17.47) maintained a statistical significance in the multivariate logistic regression, with an older age being a protective factor in developing this deficiency (OR 0.96, 95%CI 0.95-0.99). The recognition of factors that can predict the onset of AVP-D with a certain degree of accuracy enables the entire staff to pay greater attention to the patient at risk in the postoperative period, thus preventing AVP-D complications.