Adrenal Vein Sampling

Adrenal vein sampling (AVS) is an essential diagnostic tool for patients with primary aldosteronism (PA). The Endocrine Society recommends AVS as the gold standard to differentiate PA subtypes before considering adrenalectomy. PA is the most common cause of secondary hypertension. Unilateral aldosterone-producing adenoma (APA), unilateral adrenal hyperplasia, unilateral multiple adrenocortical nodules, bilateral APAs, and bilateral adrenal hyperplasia are common etiologies/subtypes of PA. After diagnosing PA based on clinical manifestations and laboratory testing, the next step in the PA workup is distinguishing unilateral APA or unilateral adrenal hyperplasia from other subtypes for surgical planning. Computed tomography (CT) and magnetic resonance imaging (MRI) are commonly utilized initial diagnostic modalities for detecting adrenal gland abnormalities. However, due to the small size of APAs and incidental non-functioning nodules, CT and MRI cannot accurately differentiate PA subtypes in most cases. AVS is the only reliable technique for identifying patients with a surgically curable subtype of PA. AVS is relatively invasive and requires considerable skill, experience, and knowledge. This chapter discusses PA, adrenal veinous anatomy, AVS techniques, potential procedure-related complications, and postprocedural care with a review of the current literature.