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SIR 2026

Traditional Poster

Venous Interventions

Session: Traditional Poster Presentations

622 - Contralateral Suppression as a Rescue Tool in Adrenal Venous Sampling: Improving Sensitivity in Unilateral Primary Aldosteronism

Monday, April 13, 2026
12:10 PM - 1:10 PM ET
Purpose: The right adrenal vein is frequently difficult to cannulate during adrenal venous sampling (AVS). In such cases, contralateral suppression indices (CSI) may be used as a rescue strategy to infer lateralization. Prior validation has emphasized unilateral disease, with few right adrenalectomy cases and limited evaluation of bilateral outcomes. We assessed CSI performance against surgical and medical outcomes and explored optimized thresholds.

Materials and Methods: We retrospectively reviewed 135 AVS cases (2022–2025). Ground truth was defined as adrenalectomy with clinical/biochemical cure (16 right, 25 left) or bilateral disease with medical management and improvement (n=17). CSI was calculated as adrenal A/C ÷ IVC A/C. Diagnostic accuracy was evaluated with ROC analysis, expert consensus thresholds (CSI < 0.5 and contralateral A/C < 9), and exploratory threshold mapping (CSI 0.1–2.5; A/C 0.5–30). Sensitivity, specificity, 95% confidence intervals, and McNemar’s test were reported.

Results: For right PA, left CSI achieved AUC 0.92. Expert consensus thresholds yielded sensitivity 0.75 (95% CI 0.47–0.91) and specificity 0.98 (0.88–1.00). Optimized thresholds (CSI < 0.7, A/C < 3.0) improved sensitivity to 0.88 (0.62–0.98) while preserving specificity 1.00 (0.91–1.00); McNemar p ≈ 0.03. For left PA, right CSI AUC was 0.97; expert consensus thresholds provided sensitivity 0.96 (0.79–0.99) and specificity 0.94 (0.80–0.99). Optimized thresholds (CSI < 0.55, A/C < 4.0) yielded identical performance; McNemar p = 0.7. In bilateral disease (n=17), contralateral indices showed no discrimination (AUC 0.49–0.68). Contralateral indices were significantly lower contralateral to the diseased side in unilateral PA (all p < 0.001, Mann–Whitney).

Conclusion: Contralateral suppression serves as a reliable rescue tool in AVS when right-sided cannulation fails. Expert consensus thresholds remain highly specific, and optimized cutoffs improved sensitivity for right PA without sacrificing specificity. CSI failed to discriminate bilateral disease, underscoring the need for full AVS and multicenter validation of refined criteria.