Bilateral sequential inferior petrosal sinus sampling with corticotrophin-releasing hormone stimulation in the diagnosis of Cushing's disease

Abstract

Objective: The demonstration of a central to peripheral ACTH gradient in a hypercortisolaemic patient is diagnostic of Cushing's disease. We tried to determine whether single blood samples for ACTH obtained sequentially from each of the inferior petrosal sinuses following human corticotrophin-releasing hormone (hCRH) stimulation can reliably establish such a gradient. Design: Prospective study. Patients: Seventeen patients with clinical and biochemical features of Cushing's syndrome. Methods: After the administration of hCRH, the patients underwent bilateral sequential inferior petrosal sinus sampling, with a single blood sample obtained from each of the inferior petrosal sinuses sequentially, along with a peripheral venous sample. The petrosal sinus catheter was withdrawn immediately after obtaining a blood sample. Patients did not require indwelling catheters in the petrosal sinuses, nor heparinisation. Results: Bilateral sequential inferior petrosal sinus sampling correctly identified a pituitary source of ACTH, as shown by a central to peripheral ACTH ratio >2, in all patients in whom the procedure was successfully carried out. All patients underwent transsphenoidal pituitary surgery resulting in remission. Conclusions: The simplified method of inferior petrosal sinus sampling, using a single sequential sample from each of the inferior petrosal sinuses, following initial hCRH stimulation, is as accurate as the more complex test using multiple bilateral simultaneous inferior petrosal sinus samples. It avoids the use of indwelling cerebral venous catheters and is therefore unlikely to cause brain stem damage.

Dexmedetomidine for Conscious Sedation in Bilateral Inferior Petrosal Sinus Sampling

“…The most reliable test to differentiate Cushing's disease from Cushing's syndrome due to ectopic ACTH production is bilateral IPSS. 4 The inferior petrosal sinuses (IPSs) receive drainage from the pituitary gland without mixture of blood from other sources. Therefore, if the ACTH levels in the IPS are high compared to an ACTH drawn in the periphery, the patient has Cushing's due to pituitary adenoma.…”

Bilateral Inferior Petrosal Sinus Sampling by Unilateral Femoral Venous Approach

“…Padayatty et al (8) described bilateral sequential IPSS with unilateral femoral venous approach. In this study, catheter was withdrawn into the superior vena cava after the right IPSS followed by the left IPSS.…”