Triphasic response after endoscopic craniopharyngioma resection and its dependency on infundibular preservation or sacrifice

OBJECTIVE Surgery is the primary treatment for craniopharyngioma with the preservation of hypothalamic function of paramount importance. Infundibular preservation is debated, as maximal resection decreases recurrence rates but causes hypopituitarism. A triphasic response of diabetes insipidus (DI), syndrome of inappropriate antidiuretic hormone secretion (SIADH), and recurrent DI has been described after pituitary surgery, but the impact of infundibular preserva- tion on the triphasic response following craniopharyngioma resection has not been well established. The authors' objec- tive was to assess postoperative fluid and sodium balance and differences in ADH imbalance management following endonasal craniopharyngioma resection based on infundibular transection status.METHODS This is a retrospective cohort study of 19 patients with craniopharyngioma treated with endoscopic en- donasal resection between 2014 and 2021. Resection was dichotomized into infundibular transection or preservation. Postoperative triphasic response, time to DI, and time to ADH replacement were compared using Fisher's exact test and Kaplan-Meier analysis.RESULTS Based on surgeon impression, 10 patients had infundibular transection and 9 had infundibular preservation. Overall, 16 patients experienced DI, 12 experienced persistent DI, and 6 experienced SIADH. A postoperative triphasic response occurred in 40% (n=4) of transection patients without preoperative DI and 11% (n=1) of preservation patients without preoperative DI. The median time to postoperative DI (0.5 vs 18.0 hours, p=0.022) and median time to ADH replacement therapy (4.5 vs 24 hours, p=0.0004) were significantly shorter in the transection group than in the preser-vation group.CONCLUSIONS Following endonasal craniopharyngioma resection, the triphasic response occurs in nearly half of infundibular transection cases. DI begins earlier with infundibular transection. On the basis of the study findings in which no patients met the criteria for SIADH or were endocrinologically unstable after postoperative day 6, it is reasonable to suggest that otherwise stable patients can be discharged at or before postoperative day 6 when ADH fluctuations have normalized and endocrinopathy is appropriately managed with oral desmopressin. Infundibular transection status may impact postoperative hormonal replacement strategies, but additional studies should evaluate their efficacies.