AVS Case Walkthrough

Adrenal vein sampling remains the gold standard for lateralizing primary aldosteronism prior to adrenalectomy, particularly when cross-sectional imaging reveals bilateral normal glands or non-functioning incidentalomas. This case walkthrough evaluates procedural execution, verifying cannulation success via selectivity indices using cortisol ratios and establishing lateralization via aldosterone-to-cortisol ratios under baseline or cosyntropin-stimulated conditions. We analyze technical pitfalls, including right adrenal vein anatomical variations, contralateral suppression dynamics, and the role of rapid intraprocedural cortisol assays. Mastering these diagnostic nuances prevents inappropriate surgical resection and ensures accurate differentiation between unilateral aldosterone-producing adenomas and bilateral adrenal hyperplasia.