Unilateral approach for bilateral petrosal sinus sampling in Cushing’s syndrome: Technical note and case series

Background: Description of a modified technique for bilateral sinus sampling in patients with Cushing’s syndrome (CS) through a unilateral approach. Methods: We reviewed the medical records of 18 patients with CS who underwent bilateral petrosal sinus sampling (PSS) at two neurosurgery centers between November 2016 and 2025. Patients with signs and symptoms of CS on physical examination, elevated plasma or urinary-free cortisol levels, and a magnetic resonance imaging of the sella turcica without pituitary lesions or with lesions smaller than 1 cm were included. We excluded patients with non-adrenocorticotropic hormone (ACTH)-dependent CS and/or expansive sellar lesions larger than 1 cm. The procedures were performed under neuroleptoanalgesia with the patient in the supine position. A right femoral vein puncture was performed, a 6Fr sheath was introduced, and it was then replaced with two 5Fr and 6Fr sheaths, enabling the introduction of two catheters to reach both inferior petrosal sinuses (IPS). Blood samples were drawn from both the IPS and from peripheral blood for analysis. Results: Cushing’s disease was diagnosed in 16 of the 18 patients. The two remaining patients had an ACTH-secreting carcinoid tumor in the lung. No complications were reported. Conclusion: This original, unilateral right femoral vein approach was effective for bilateral PSS.