134 - The Right Adrenal Vein Bubble Sign: A Specific Imaging Landmark for Successful Cannulation in Adrenal Vein Sampling

Monday, March 31, 2025

12:10 PM – 1:10 PM CT

Location: Music City Center, Expo Poster Area

Author/Co-author(s)

Jagteshwar Sandhu, MD

Medical Resident
University of Miami, United States
Jack Lin, BA

Medical Student
University of Miami, United States
EH

Erik Hilborn, MD

Medical Resident
University of Miami, United States
NS

Nikita Sharma, BS

Medical Student
University of Miami, United States

Poster Presenter(s)

Marisela Neff (she/her/hers)

Medical Student
University of Miami, United States

Author/Co-author(s)

Konrad Kozlowski, BA

Medical Student
University of Miami, United States
Chloe E. Issa, BS

Medical Student
University of Miami, United States
EG

Eva Garcia, None

Undergraduate Student
Florida State University, United States
ZM

Zoe Miller, MD

Asst. Prof. of Clinical Interventional Radiology; Associate Program Director of IR Residency Program
University of Miami, United States

Purpose: Cannulation of the right adrenal vein (RAV) during adrenal vein sampling (AVS) is difficult due to its small size, variable anatomy, and proximity to the IVC. To improve success rates, the identification of reliable anatomical and imaging landmarks is of interest. Previous studies have explored landmarks, such as the emissary veins and the accessory hepatic vein, that aided in successful cannulations {1,2}. In this study, we investigate the utility of a novel fluoroscopic imaging marker, the "bubble sign", identified during contrast injection proximal to the right adrenal vein. This study evaluates the specificity and predictive value of the bubble sign for successful RAV cannulation.

Materials and Methods: 68 patients who underwent AVS were analyzed in a retrospective study. During the procedures, the "bubble sign" was identified as a contrast induced fluoroscopic feature proximal to the RAV. The presence or absence of this bubble sign was recorded for each patient. Successful cannulation of the RAV was defined by achieving a selective index (SI) greater than 5. Descriptive analysis was performed to evaluate the frequency of the bubble sign and its association with successful cannulation. Due to the observational nature of the study, no inferential statistical tests were used beyond descriptive metrics.

Results: Among 68 patients, 40 patients (58.8%) demonstrated the RAV bubble sign on fluoroscopy. Of these, 38 patients (95.0%) had successful cannulation of the RAV with an SI greater than 5, while 1 patient had unsuccessful cannulation, and 1 patient had no reported lab results. In the 28 patients (41.2%) who did not exhibit the bubble sign, 24 patients (85.7%) achieved successful cannulation. The presence of the bubble sign was observed to be a highly specific indicator of successful cannulation, as nearly all patients with the sign had an SI > 5. However, the absence of the bubble sign did not exclude the possibility of successful cannulation. These findings suggest that the bubble sign is a useful imaging marker for guiding adrenal vein sampling.

Conclusion: The RAV bubble sign is a specific and reliable imaging marker for successful cannulation during AVS, significantly increasing the likelihood of successful cannulation. While the bubble sign is highly predictive when present, its absence does not rule out successful cannulation. This landmark should be utilized to improve cannulation success rates, but clinicians should not solely rely on its presence to guide procedural decisions. Further studies are warranted to investigate the nature of the bubble sign.