Selective venous sampling directly from cavernous sinus in Cushing's syndrome

Area of Science:

• Endocrinology
• Interventional Radiology
• Neurosurgery

Background:

• Cushing's disease diagnosis relies on accurate localization of ACTH-secreting pituitary adenomas.
• Inferior petrosal sinus sampling is a standard but invasive method for lateralizing ACTH sources.
• Alternative venous sampling techniques may offer improved diagnostic yield and safety.

Purpose of the Study:

• To evaluate the efficacy of superselective catheterization and venous sampling directly from the cavernous sinus for diagnosing Cushing's disease.
• To compare ACTH and prolactin (PRL) gradients in the cavernous sinus versus peripheral circulation.
• To assess the diagnostic accuracy and safety of this novel sampling method.

Main Methods:

• Superselective catheterization and venous sampling from the cavernous sinus in seven Cushing's disease patients and one ectopic ACTH syndrome patient.
• Measurement of ACTH and PRL levels in cavernous sinus, peripheral, inferior petrosal sinus, and jugular vein samples.
• Calculation of central/peripheral (c/p) and intercavernous sinus gradients.

Main Results:

• Cavernous sinus ACTH c/p gradients were significantly higher in Cushing's disease (mean, 49.6) than inferior petrosal sinus gradients (mean, 14.0).
• Intercavernous ACTH gradients correctly lateralized the tumor in all but one patient with a midline adenoma.
• Ectopic ACTH syndrome showed no significant ACTH gradients in either sinus.
• PRL gradients were smaller than ACTH gradients and provided less reliable lateralization, especially for midline tumors.

Conclusions:

• Selective cavernous sinus sampling provides reliable diagnostic ACTH gradients (>10) for Cushing's disease.
• CRH stimulation and simultaneous PRL measurement are unnecessary for this technique.
• High pituitary hormone concentrations obtained may facilitate further clinical investigations.