No Incremental Benefit of Coil-Assisted Over Ethanol Embolization in Unilateral Primary Aldosteronism

Abstract Background Selective adrenal arterial embolization (SAAE) is an alternative treatment for unilateral primary aldosteronism (PA), but its overall success remains variable. We evaluated whether coil-assisted ethanol embolization (Coil-E) improves outcomes compared with ethanol embolization alone in patients undergoing single-vessel SAAE. Methods In this retrospective study, patients with unilateral PA who underwent single-vessel SAAE between 2020 and 2021 were categorized into Coil-E and ethanol groups. The primary endpoint was clinical success at 12 months defined according to the Primary Aldosteronism Surgical Outcome (PASO) criteria. Secondary endpoints included biochemical success, changes in 24-hour ambulatory blood pressure (BP), and safety outcomes. Propensity score–based analyses were performed. Results Eighty-two patients were included (23 Coil-E, 59 ethanol). At 12 months, complete clinical success occurred in 17.4% vs. 20.3%, partial success in 47.8% vs. 35.6%, and absent success in 34.8% vs. 44.1% (Coil-E vs. ethanol; all P > 0.05). Complete biochemical success occurred in 39.1% vs. 55.9%, whereas absent biochemical success occurred in 34.8% vs. 28.8%. Mean 24-hour systolic/diastolic BP decreased by 21.6/10.1 mmHg in the Coil-E group and 20.5/9.7 mmHg in the ethanol group, with no significant between-group differences. Serum potassium and aldosterone improved in both groups without deterioration in renal function or cortisol levels. No major procedure-related complications occurred. Findings were consistent across adjusted analyses. Conclusion Among patients with unilateral PA undergoing single-vessel SAAE, Coil-E was not associated with improved PASO-defined clinical or biochemical success compared with ethanol embolization alone.