119 - Assessing Differences in the Diagnostic Adequacy of Left Sided Versus Right Sided Adrenal Vein Sampling

Monday, March 31, 2025

12:10 PM – 1:10 PM CT

Location: Music City Center, Expo Poster Area

Poster Presenter(s)

Scott M. Pierce, MD

PGY-3 IR/DR
Oregon Health & Science University, United States

Author/Co-author(s)

KQ

Keith Quencer, MD (he/him/his)

Associate Professor of Interventional Radiology, School of Medicine; Section Chief of IR Body
Oregon Health and Science University, United States
Brian Park, MD, MS

Assistant Professor
Oregon Health & Science University, United States

Purpose: To assess laterality differences in sampling adequacy for AVS performed without cosyntropin stimulation.

Materials and Methods: Forty-six patients had AVS performed with pre and post cosyntropin stimulation between April 2022 and June 2024. Sampling was performed through a 5fr catheter without ACTH stimulation. Then, 250 µg of cosyntropin is given by IV bolus and repeat sampling is performed after 15 minutes. Right sided samples were obtained in the right adrenal vein, and left sided samples were obtained at the common adreno-phrenic trunk. Angiography confirmed consistent catheter positioning. All cases had diagnostic post-stimulated sampling using a selectivity index (SI) > 3.0. Pre-stimulation selectively indices (SI) of >2.0 was used as threshold for adequacy. Samples were divided into left and right and were compared using chi-squared tests.

Results: Of the 46 tests, 26 (56.5%) of the unstimulated samples did not achieve diagnostic adequacy. There was a significant difference in laterality of the diagnostically inadequate samples, 7 occurred bilaterally (27%), 17 occurred on the left only (65%) and 2 occurred on the right only (8%) X2 (1, N = 92) = 10.63, p = 0.001. The median unstimulated nondiagnostic SI for both right and left sampling was 2.78. There was a significant difference in median SI value on the left and the right (left = 1.8 vs right = 3.81) X2 (1, N = 92) = 10, p = 0.002.

Conclusion:

Using current selectivity index of 2, unstimulated AVS had a high rate of non-diagnostic sampling (56.5% compared to 0% for stimulated sampling). 92% (24/26) of these sampling inadequacies involved the left side. All post-stimulation sampling was adequate and catheter positioning was judged to be equivalent on both pre and post stimulation. These findings suggest that an unstimulated SI threshold of 2.0 may be too rigorous, particularly for samples of the left adrenal vein. Alternatively, these results also suggest that for unstimulated AVS, to reliably reach adequacy threshold on the left, sampling at the left adrenal vein proper rather than the adreno-phrenic trunk may be necessary to avoid significant dilution by systemic blood.