Endocrine Abstracts

Introduction: Primary Aldosteronism (PA) is a leading cause of secondary hypertension. Adrenal venous sampling (AVS) remains the gold standard for differentiating unilateral from bilateral disease. However, AVS is technically challenging, with variable success rates. Our current recommendation is for all surgical candidates to undergo AVS. This audit aimed to evaluate technical success and post-adrenalectomy outcomes for patients undergoing AVS.

Methods: We conducted a retrospective audit of AVS procedures performed at King’s College Hospital between October 2023 and May 2024. Successful adrenal cannulation was defined as adrenal/peripheral vein cortisol ratio > 5:1 with synacthen infusion. Post-operative biochemical remission was defined by saline-suppression test (SST) demonstrating aldosterone < 200 pmol/l (Diasorin Liaison XL). Follow-up data included management undertaken and outcomes post-adrenalectomy.

Results: Of the patients referred for AVS, 26/33 underwent the procedure. All patients had PA based on either aldosterone-renin ratio (19%) or SST (81%), with a mean aldosterone nadir of 756 pmol/l. Prior to AVS, 35% of patients were prescribed ≥3 antihypertensives and 85% had hypokalaemia. Bilateral adrenal vein cannulation was technically successful in 88% of procedures and 74% showed lateralisation of aldosterone secretion. Only 7 patients underwent adrenalectomy. Of these, 5/7 achieved complete biochemical remission, and 3/7 completely discontinued anti-hypertensives. Of the 2 patients with no biochemical remission, one had an AVS lateralisation ratio of >7, but bilateral secretion was noted. Histology showed micronodular disease. The other case had unsuccessful right-sided cannulation and elected for surgery based on a radiological left-sided nodule. These cases demonstrated some improvement in blood pressure control but remained on anti-hypertensives.

Discussion: This audit demonstrates a high success rate of bilateral adrenal vein cannulation. Some patients are still awaiting surgery, limiting the scope of analysis. A high proportion of patients demonstrate clinical benefit from surgery. This data will refine our multi-disciplinary decision-making and case selection.