Cavernous sinus sampling in patients with adrenocorticotrophic hormone—dependent Cushing's syndrome with emphasis on inter- and intracavernous adrenocorticotrophic hormone gradients

Object. As an alternative method to inferior petrosal sinus sampling with administration of corticotropin-releasing hormone (CRH), the authors have developed a method of selective venous sampling directly from the cavernous sinus, which is performed using a superselective catheterization technique. The goal of this study is to assess this method. Methods. Catheterization to the cavernous sinus was performed in 44 patients with clinical and biochemical features of Cushing's syndrome. Forty of these patients in whom there was a definite clinical and/or histological diagnosis were evaluated. In 35 patients, a pituitary microadenoma was detected on magnetic resonance imaging and/or during surgery. Ectopic lesions were suspected in five patients, who later developed nonpituitary tumors. The central/peripheral (C/P) ratios of adrenocorticotrophic hormone (ACTH) without CRH administration ranged from 5.2 to 448.1 (mean ± standard deviation, 66.7 ± 91.2) in cavernous sinuses and from 1.1 to 52 (mean ± standard de...