Intraprocedural cortisol testing improves adrenal vein cannulation success and diagnostic accuracy in assessment of primary aldosteronism, in a medium throughput centre

Accuracy of semi-quantitative gold nanoparticle-based quick cortisol assay with and without adrenocorticotropic hormone infusion during adrenal vein sampling

Adrenal vein sampling (AVS) is the gold standard for diagnosing unilateral primary aldosteronism. Point-of-care rapid cortisol assays such as the gold nanoparticle based quick cortisol assay (QCA) are used to confirm accurate cannulation of the adrenal veins during the procedure and have improved AVS success rates. In this retrospective cohort study, we reviewed the results of consecutive AVS procedures (n = 37) performed with and without ACTH (synacthen) infusion between October 2020 and December 2022 at our institution. We compared (1) the accuracy of point-of-care QCA at semi-quantitatively assessing successful adrenal vein cannulation before and after ACTH infusion when compared with selectivity index based on laboratory cortisol measurements, (2) accuracy of QCA based on peripheral and adrenal vein cortisol levels and (3) the impact of time of day on the accuracy of QCA. We found the accuracy of QCA compared with formal laboratory cortisol measurements was 71% pre-ACTH and 100% post-ACTH (p-value < 0.001). Pre-ACTH, the accuracy of QCA was higher in the lowest (28-257 nmol/L) and highest (466-25130 nmol/L) adrenal vein cortisol tertiles compared to the mid-tertile. Post-ACTH, the accuracy of QCA remained high regardless of adrenal vein cortisol levels. Time of day did not affect the accuracy of the QCA. We conclude that during basal AVS subjective, visual estimates of adrenal vein cortisol levels using the QCA semi-quantitively should not be solely relied upon to guide catheter placement. These results will help guide clinicians in the appropriate clinical situations in which QCA should be used during AVS.

Adrenal Vein Sampling for Primary Aldosteronism: Recommendations From the Australian and New Zealand Working Group

Adrenal vein sampling (AVS) is the current recommended procedure for identifying unilateral subtypes of primary aldosteronism (PA), which are amenable to surgery with the potential for cure. AVS is a technically challenging procedure usually undertaken by interventional radiologists at tertiary centres. However, there are numerous variations in AVS protocols relating to patient preparation, sampling techniques and interpretation which may impact the success of AVS and patient care. To reduce practice variations, improve the success rates of AVS and optimise patient outcomes, we established an Australian and New Zealand AVS Working Group and developed evidence-based expert consensus recommendations for the preparation, performance and interpretation of AVS. These recommendations can be used by all healthcare professionals in a multidisciplinary team who look after the diagnosis and management of PA.

Using Point of Care Rapid Cortisol Measurement During Adrenal Venous Sampling in Primary Hyperaldosteronism

Objectives: To assess success rates and cost-effectiveness of adrenal venous sampling (AVS) after implementing point-of-care rapid cortisol (RC) testing conducted using a europium nanoparticle-based fluoro-immunoassay in patients with primary hyperaldosteronism. Methods: A retrospective review of AVS procedures was conducted at our medical center between January 2016 and June 2024. The primary objective was to compare the success rates of AVS before and after the implementation of the RC testing. Secondary outcomes included a cost-benefit analysis. Results: Of 55 AVS procedures, 19 were conducted using RC testing and 36 were in the historical control cohort. The success rates for right vein sampling were 79% and 67%, respectively. Overall, in six (31.5%) patients in the RC cohort, a low RC selectivity index (SI) value, calculated within 10 min, enabled determination of unsuccessful cannulation and need for resampling during the same AVS session. Repeated sampling resulted in successful procedures in two cases (10.5%) and unsuccessful AVS in four cases, nonetheless sparing the need for repeated AVS sessions in 31.5% of cases. Utilizing RC potentially spared 6 patients from repeated AVS sessions, and considering the additional expenses on the RC test, its use afforded cost savings of an average of $1288 per patient. Conclusions: We demonstrated the cost-effectiveness of utilizing RC measurement in sparing the need for repeated AVS sessions. RC measurement during AVS enabled identification of correct catheter placement in real time, allowing for prompt decisions regarding the need for additional sampling attempts, thereby reducing subsequent costs of repeated AVS sessions.

Adrenal Vein Sampling: Tips and Tricks

Adrenal vein sampling (AVS) is the standard method for distinguishing unilateral from bilateral sources of autonomous aldosterone production in patients with primary aldosteronism. This procedure has been performed at limited specialized centers due to its technical complexity. With recent advances in imaging technology and knowledge of adrenal vein anatomy in parallel with the development of adjunctive techniques, AVS has become easier to perform, even at nonspecialized centers. Although rare, anatomic variants of the adrenal veins can cause sampling failure or misinterpretation of the sampling results. The inferior accessory hepatic vein and the inferior emissary vein are useful anatomic landmarks for right adrenal vein cannulation, which is the most difficult and crucial step in AVS. Meticulous assessment of adrenal vein anatomy on multidetector CT images and the use of a catheter suitable for the anatomy are crucial for adrenal vein cannulation. Adjunctive techniques such as intraprocedural cortisol assay, cone-beam CT, and coaxial guidewire-catheter techniques are useful tools to confirm right adrenal vein cannulation or to troubleshoot difficult blood sampling. Interventional radiologists should be involved in interpreting the sampling results because technical factors may affect the results. In rare instances, bilateral adrenal suppression, in which aldosterone-to-cortisol ratios of both adrenal glands are lower than that of the inferior vena cava, can be encountered. Repeat sampling may be necessary in this situation. Collaboration with endocrinology and laboratory medicine services is of great importance to optimize the quality of the samples and for smooth and successful operation. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Intraprocedural Cortisol Measurement Increases Adrenal Vein Cannulation Success Rate in Primary Aldosteronism: A Systematic Review and Meta-analysis

BACKGROUND

This study aimed to explore the effectiveness of intraprocedural cortisol measurement (IPCM) for the technical success rates of bilateral adrenal vein, right adrenal vein (RAV), and left adrenal vein (LAV) cannulation during adrenal vein sampling (AVS).

METHODS

Systematic searches of PubMed, Embase, Cochrane Library, and ClinicalTrials.gov were performed from database inception to May 10, 2023, without any restrictions. We estimated the overall effect estimates of outcomes using the Mantel-Haenszel random-effects model. We conducted subgroup analyses, meta-regression, and sensitivity analysis to explore the possible sources of between-study heterogeneity.

RESULTS

In total, 3,485 patients from 11 studies (three prospective and eight retrospective) were enrolled. Bilateral selectivity in patients who underwent IPCM during AVS was significantly higher than that in patients who underwent a routine AVS procedure (84% vs. 64%, RR 1.42, 95% confidence interval [CI]: 1.27-1.59, P < 0.01), with significant heterogeneity (I2 = 68%). A 42% relative risk reduction in the failure rate of bilateral adrenal vein cannulation was found in the IPCM group. Moreover, pooled analysis showed a significant increase in the success rates of RAV cannulation (84% vs. 72%, RR 1.21, 95% CI 1.12-1.31, P < 0.01, I2 = 33%) and LAV cannulation (89% vs. 84%, RR 1.05, 95% CI 1.02-1.08, P < 0.01, I2 = 4%) when IPCM was implemented during the AVS procedure compared to the routine AVS procedure.

CONCLUSIONS

An IPCM-based strategy during AVS appears to have a significant beneficial effect on improving the success rate of bilateral cannulation, RAV cannulation and LAV cannulation.

A clinical assessment of portable point-of-care testing for quick cortisol assay during adrenal vein sampling

This study assessed the clinical performance of point-of-care testing (POCT) for quick cortisol assay (QCA) during adrenal vein sampling (AVS) using a newly invented portable quantitative assay instrument. An observational study was conducted prospectively at two centres in Japan. Forty-eight patients with primary aldosteronism considered for adrenalectomy were enrolled in this study and underwent AVS. Three basal adrenal vein samples from each adrenal vein and two from the inferior vena cava were collected sequentially. The cortisol concentration of adrenal vein samples was measured by routine method and QCA. A total of 338 adrenal vein samples were analysed from 250 sites to determine AVS success or failure. The distribution of turnaround time of the QCA for AVS success or failure followed a normal distribution with an average of 20.5 min. A positive correlation between the routine method and QCA was observed regarding cortisol concentration or selectivity index. No significant difference between the two methods was observed regarding the success rate of AVS. Using the routine method as a reference, the sensitivity and specificity of AVS success or failure were 99.1% (210/212) and 81.6% (31/38), respectively. Easy, quick, portable, and precise POCT-QCA demonstrated its compatibility with routine methods regarding clinical performance.