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Objective:
Adrenal vein (AV) sampling is a crucial component of the management of primary hyperaldosteronism; however, success rate is variable given the technical challenges of selecting the Right AV, thereby impeding the identification of potential surgically-curative cases. Intraprocedural cone beam CT (CBCT) may increase the success rate of AV sampling; however, this potential benefit is underreported due to operator/technical variation across institutions and small patient population. This study aims to determine whether CBCT increases the success rate of cosyntropin-stimulated AV sampling.

Materials and Methods:
A retrospective chart review was conducted at a single institution from 2018 to 2023 on patients with primary hyperaldosteronism who underwent cosyntropin-stimulated AV sampling with confirmation of cannulation of the Right AV either by venography alone or with additional CBCT. Preprocedural data such as patient demographics, serum renin:aldosterone (SRA), and adrenal cross-sectional imaging were collected. Intraprocedural data such as fluoroscopy time, dose area product (DAP), and IV contrast volume were collected. The selectivity and lateralization indices were calculated for all cases; as per expert consensus, a selectivity index of > 5 was deemed unequivocally successful and a lateralization Index of > 4.0 was deemed unequivocal for laterization. A Fishers exact test was conducted to assess a statistically significant difference between the success rate of the two cohorts. Of successful cases, lateralization (or lack thereof) was correlated with preprocedural imaging of the adrenal glands.

Results:
Twenty-nine patients underwent AV sampling confirmed by venography, and 30 patients underwent AV sampling with additional CBCT. No statistical difference between age, sex, or SRA was observed between the two cohorts. The first cohort yielded a success rate of 62.1% and the second cohort yielded a success rate of 90.0% (<em>p</em> = 0.015). Additionally, of the patients who underwent successful AV sampling from both cohorts, no statistically significant difference was observed between fluoroscopy time, contrast volume, or DAP. Of note, 64.4% of successful AV samplings were incongruent with preprocedural adrenal imaging.

Conclusion:
AV sampling serves an important role in the work-up and management of primary aldosteronism, as it identifies patients eligible for surgical management versus those better managed with medical therapy; however, AV sampling is a challenging procedure with variable diagnostic success rates. Even within the inherent limitations of a retrospective cohort study at a single institution with 59 patients, this study provides evidence that CBCT increases the diagnostic yield of AV sampling, preventing the need for repeat procedures. Furthermore, the implementation of CBCT appears to be a safe maneuver without increased exposure to radiation or IV contrast. Therefore, the incorporation of CBCT as a routine practice during AV sampling is likely to improve the diagnostic yield of the procedure.