"Double-Down" Adrenal Vein Sampling Results in Patients with Apparent Bilateral Aldosterone Suppression: Utility of Repeat Sampling including Super-Selective Sampling.

Purpose: To report outcomes of patients undergoing adrenal vein sampling (AVS) for primary aldosteronism with results indicating apparent bilateral adrenal suppression (ABAS), in which the adrenal aldosterone-to-cortisol ratios are decreased bilaterally ("double-down") compared to the non-adrenal sample, and evaluate repeat AVS results.

Materials And Methods: Between 2003 and 2020, 762 patients underwent AVS. Twenty patients (2.6%; male, 12; female, 8; age 50.3 ± 9.7 years) with ABAS on initial AVS were identified. Ten underwent repeat AVS. Super-selective AVS (SS-AVS) was employed in 6 of 10 repeat AVS (60%). Outcomes after AVS were analyzed. A lateralization index (LI) >4 was considered an indication for adrenalectomy.

Results: Repeat AVS was diagnostic in 70% of patients (n = 7), with 6 of 7 lateralizing with LI >4 (median LI = 32.3; range 4.6-54.8) and 1 of 7 nearly lateralizing (LI = 3.5). All 7 patients underwent adrenalectomy. ABAS was redemonstrated in 3 patients (30%): 2 with unilateral adenomas on cross-sectional imaging underwent adrenalectomy despite ABAS results and 1 was lost to follow-up. Four of 6 patients (66%) who underwent SS-AVS were diagnosed with unilateral disease (median LI = 43.3; range 23.9-54.8), with one patient's diagnosis reliant upon a single super-selective sample. In total, 9 patients underwent adrenalectomy after repeat AVS, all of whom had improved blood pressure control postoperatively. Ten patients did not undergo repeat AVS: 6 were lost to follow-up, 3 underwent medical management, and 1 underwent adrenalectomy.

Conclusions: AVS should be repeated when "double-down" ABAS results are encountered. Super-selective sampling may provide worthwhile diagnostic data when employed during repeat AVS.