Role of adrenal vein sampling in primary aldosteronism: the Monash Health experience

Adrenal vein sampling (AVS) is useful for distinguishing unilateral versus bilateral hypersecretion in primary aldosteronism (PA), but is technically challenging. Furthermore, the use of adrenocorticotropic hormone (ACTH)-stimulation in AVS is controversial. We implemented a Monash Health-specific AVS protocol in 2010.

The audit aimed to: (i) examine the impact of a dedicated protocol on success rates of AVS at a tertiary referral centre; (ii) evaluate the impact of AVS on sub-typing of PA; and (iii) assess the utility of ACTH stimulation in AVS.

AVS was performed on patients with PA confirmed by positive saline suppression testing (aldosterone level >140 pmol/L post-saline infusion), with sequential sampling of adrenal and peripheral veins, pre- and post-ACTH infusion. Patients with unilateral aldosterone-producing adenoma diagnosed on successful AVS were referred for adrenalectomy.

Between 2010 and 2014 inclusive, a total of 28 AVS procedures was performed, with complete pre- and post-ACTH data for 19 procedures. Bilateral successful cannulation rates improved post-implementation of our protocol (61% vs 41%). Of the patients, 32% had discordant imaging and AVS results: four patients with unilateral adenomas did not lateralise on AVS and were managed medically; four patients with bilateral or no adenomas on imaging, lateralised on AVS and had surgery. Overall, use of ACTH did not increase successful cannulation and tended to mask lateralisation.

AVS is crucial in subtype classification of PA and should be performed by a dedicated radiologist with a standardised protocol. AVS outcomes were not improved with the use of ACTH stimulation.