Lateralization outcomes of bilateral inferior petrosal sinus sampling: desmopressin vs CRH.

Abstract

Bilateral inferior petrosal sinus sampling (BIPSS) is the gold standard for localizing ACTH-dependent Cushing's syndrome (CS). While corticotropin-releasing hormone (CRH) was initially used for stimulation, desmopressin has become a common alternative. This research evaluates desmopressin's effectiveness in lateralizing Cushing's disease (CD) during BIPSS compared to CRH stimulation. The study included 33 individuals with ACTH-dependent CS who underwent BIPSS and had diagnoses confirmed by endoscopic endonasal transsphenoidal pituitary surgery (EETPS). Fourteen participants underwent BIPSS with CRH and 19 with desmopressin. A comparative analysis was conducted. BIPSS accurately lateralized 76% of cases, specifically, 71% with CRH and 79% with desmopressin (p = 0.2). For tumors < 6mm on MRI, overall accuracy was 82%, namely, 75% with CRH and 90% with desmopressin (p = 0.4). IPSS achieved 100% accuracy in the four cases with no lesion on preoperative MRI. This study demonstrates no significant difference in lateralization accuracy between desmopressin and CRH for IPSS. In challenging cases, especially those with microadenomas or non-lesional CD, desmopressin with IPSS aids in preoperative lateralization.