Craniopharyngiomas and giant invasive pituitary adenomas, with lesions originating from the pituitary stalk, are frequently associated with intraoperative and postoperative diabetes insipidus (DI). DI can lead to hypernatremia, and the rapid elevation of serum sodium within hours can precipitate acute brain tissue shrinkage, potentially resulting in devastating complications including intracerebral hemorrhage, cerebral venous sinus thrombosis, seizures, somnolence, and coma. Furthermore, dehydration secondary to DI may compromise organ perfusion and enhance anaerobic glycolysis in tissues, leading to hyperlactatemia and even lactic acidosis. However, the currently available evidence is insufficient to support the routine prophylactic anti-diuretic therapy during surgery.This study aims to evaluate the efficacy and safety of prophylactic low-dose continuous intravenous dDAVP infusion in patients undergoing surgery for complex sellar region lesions, with respect to reducing the incidence of hypernatremia occurring during surgery or within the first 24 hours postoperatively.