Clinical Management and Outcomes of Adrenal Hemorrhage Following Adrenal Vein Sampling in Primary Aldosteronism

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.

Strategies for subtyping primary aldosteronism

Adrenal venous sampling (AVS) is a crucial method for the lateralization of primary aldosteronism (PA). It is advised to halt the use of the patient's antihypertensive medications and correct hypokalemia prior to undergoing AVS. Hospitals equipped to conduct AVS should establish their own diagnostic criteria based on current guidelines. If the patient's antihypertensive medications cannot be discontinued, AVS can be performed as long as the serum renin level is suppressed. The Task Force of Taiwan PA recommends using a combination of adrenocorticotropic hormone stimulation, quick cortisol assay, and C-arm cone-beam computed tomography to maximize the success of AVS and minimize errors by using the simultaneous sampling technique. If AVS is not successful, an NP-59 (131 I-6-β-iodomethyl-19-norcholesterol) scan can be used as an alternative method to lateralize PA. We depicted the details of the lateralization procedures (mainly AVS, and alternatively NP-59) and their tips and tricks for confirmed PA patients who would consider to undergo surgical treatment (unilateral adrenalectomy) if the subtyping shows unilateral disease.

Surgery based on computed tomography images might be feasible for primary aldosteronism patients with visible unilateral adenoma

Primary aldosteronism (PA) with unilateral adrenal disease can be cured or improved by adrenalectomy. Adrenal venous sampling (AVS) is recommended to identify patients for surgical management. However, surgeries based on computed tomography (CT) images are only advocated for PA patients aged <35 with visible unilateral adenoma. Herein, we aimed to compare CT-based and AVS-based surgery outcomes for PA patients with visible unilateral adenomas for different age groups. A total of 178 PA patients who underwent unilateral adrenalectomy between June 2018 and January 2021 were included in the study based on CT (n = 54) or AVS (n = 124). Demographics, diagnostics, and follow-up data were retrospectively collected. Clinical and biochemical outcomes were analyzed according to Primary Aldosteronism Surgical Outcome (PASO) criteria at 1-year follow-up. Our results showed that complete clinical success (46.3% vs. 47.6%, p = 0.875) and complete biochemical success (88.8% vs. 91.9%, p = 0.515) were similar between the two groups. Age stratification revealed that patients >55 years old were likely to have worse biochemical outcomes; however, these were still not significantly different (21.4% vs. 8.6%, p = 0.220). Of the 114 AVS-based patients who achieved complete biochemical success, 37 (32.4%) with bilateral normal or bilateral abnormal CT images changed treatment options according to AVS results, 1 (0.9%) avoided adrenalectomy on the wrong side. Our results indicated that surgery based on CT images might be feasible for highly selected PA patients with visible unilateral adenomas and less limited by age, while for those with normal adrenal or bilateral adrenal lesions, treatment strategy must be decided by AVS.

Hemorrhage from Adrenal Vein Rupture during Adrenal Vein Sampling

We describe a case of right adrenal hemorrhage from adrenal vein sampling treated conservatively with overnight admission and pain control. We review the existing literature on rates of this complication, typical clinical outcomes, and practical tips to avoid its occurrence.

Contrast medium free selective adrenal vein sampling in the management of primary aldosteronism

BACKGROUND

To analyze contrast free adrenal vein sampling (AVS) for differentiating unilateral from bilateral disease in patients diagnosed with hypertension due to primary aldosteronism (PA).

METHODS

Consecutive patients with PA and subsequent contrast medium free AVS between April 2015 and March 2020 were retrospectively included. Cross-sectional imaging (CSI), AVS and clinical data were analyzed regarding diagnostic performance. In addition, patients with lateralisation receiving adrenalectomy were compared to a control group treated with mineralocorticoid antagonists.

RESULTS

In total 186 patients with AVS were included. The success rate for bilateral catheterization was 88% (median effective dose 2.8 mSv). CSI had an accuracy of 60% (CI: 0.52-0.67) in the detection of lateralization compared to AVS. Patients with bilateral adrenal hyperplasia and those with aldosterone-producing adenoma did not differ in systolic blood pressure (sBP) (p = 0.63) or number of antihypertensive drugs (NAD) (p = 0.11). After adrenalectomy, 28 patients were cured (51%; sBP ≤130 mmHg, NAD = 0), 18 were improved (33%; decrease of sBP ≥20 mmHg and NAD), and 8 were unchanged (15%). Serum renin increased significantly after treatment (p < 0.01).

CONCLUSION

Contrast medium free AVS is a reliable procedure in the diagnostic management of patients with PA with high technical success rate. The accordance between CSI and results from AVS was only moderate indicating the central role of AVS in the diagnostic work-up of patients with PA. Patients with predominant disease diagnosed with AVS had a high cure rate and/or significant improvement after adrenalectomy.

Approach to the Patient With Adrenal Hemorrhage

Adrenal hemorrhage is an uncommon, underrecognized condition that can be encountered in several clinical contexts. Diagnosing adrenal hemorrhage is challenging due to its nonspecific clinical features. Therefore, it remains a diagnosis that is made serendipitously on imaging of acutely unwell patients rather than with prospective clinical suspicion. Adrenal hemorrhage can follow abdominal trauma or appear on a background of predisposing conditions such as adrenal tumors, sepsis, or coagulopathy. Adrenal hemorrhage is also increasingly reported in patients with COVID-19 infection and in the context of vaccine-induced immune thrombocytopenia and thrombosis. Unexplained abdominal pain with hemodynamic instability in a patient with a predisposing condition should alert the physician to the possibility of adrenal hemorrhage. Bilateral adrenal hemorrhage can lead to adrenal insufficiency and potentially fatal adrenal crisis without timely recognition and treatment. In this article, we highlight the clinical circumstances that are associated with higher risk of adrenal hemorrhage, encouraging clinicians to prospectively consider the diagnosis, and we share a diagnostic and management strategy.

First survey on the diagnosis and treatment of primary aldosteronism by Spanish Endocrinology and Nutrition specialists

OBJECTIVE

To evaluate the indication and the resources for the screening/diagnosis of primary aldosteronism (PA) in Endocrinology units in Spain.

MATERIAL AND METHODS

An anonymous 2-phase (2020/2021) online survey was conducted by the AdrenoSEEN group among SEEN members with data about screening, confirmation tests, availability of catheterisation and the treatment of PA.

RESULTS

Eighty-eight (88) specialists completed the survey. Plasma aldosterone concentration and plasma renin activity were available at all centres; urinary aldosterone was available in 55% of them. The most frequent indications for determining the aldosterone/renin ratio (ARR) were adrenal incidentaloma (82.6%), hypertension with hypokalaemia (82.6%), hypertension in patients <40 years (79.1%) and a family history of PA (77.9%). 61% and 18% of the respondents used an ARR cut-off value of PA of ≥30 and 20ng/dl per ng/mL/, respectively. The intravenous saline loading test was the most commonly used confirmatory test (66.3%), followed by the captopril challenge test (24.4%), with the 25mg dose used more than the 50mg dose (65% versus 35%). 67.4% of the participants confirmed the availability of adrenal vein catheterization (AVC). 41% of this subgroup perform it with a continuous infusion versus 30.5% with an ACTH (1-24) bolus, whereas 70.3% employ sequential adrenal vein catheterization. 48% of the participants reported an AVC success <50%. Total laparoscopic adrenalectomy was the treatment of choice (90.6%), performed by specialists in General and Digestive Surgery specialising in endocrinological pathology.

CONCLUSION

PA screening and diagnostic tests are extensively available to Spanish endocrinologists. However, there is a major variability in their use and in the cut-off points of the diagnostic methods. The AVS procedure remains poorly standardised and is far from delivering optimal performance. Greater standardisation in the study and diagnosis of PA is called for.

Imaging or Adrenal Vein Sampling Approach in Primary Aldosteronism? A Patient-Based Approach

Primary aldosteronism (PA) is the most frequent cause of secondary hypertension, associated with an increased risk of cardiovascular and cerebral disease, compared to essential hypertension. Therefore, it is mandatory to promptly recognize the disease and offer to the patient the correct diagnostic-therapeutic process in order to reduce new-onset cardiovascular events. It is fundamental to define subtype classification (unilateral or bilateral disease), in order to provide the best treatment (surgery for unilateral and medical treatment for bilateral disease). Here, we report five clinical cases of different subtypes of PA (patients with monolateral or bilateral PA, nondiagnostic AVS, allergy to iodinated contrast, and patients not suitable for surgery), with particular attention to the diagnostic-therapeutic process and the different approaches tailored to a single case. Since PA is a spectrum of various diseases, it needs a personalized diagnostic-therapeutic process, customized for the individual patient, depending on previous medical history, suitability for the surgery and patient's preferences.

Adrenal venous sampling in primary aldosteronism: Experience of a Spanish multicentric study (Results from the SPAIN-ALDO Register)

OBJECTIVE

The aim of this study was to evaluate the rate of adrenal venous sampling (AVS) performance in patients with primary aldosteronism (PA), the main reasons for its non-performance, and the success and complications rate of this procedure in Spain. Moreover, the concordance between CT/MRI and AVS for PA subtyping was evaluated.

METHODS

A retrospective multicenter study of PA patient follow-up in 20 Spanish tertiary hospitals between 2018-2021 was performed (SPAIN-ALDO Register).

RESULTS

Of the 440 patients with PA included in the study, 153 underwent AVS (34.8%). The main reasons for not performing AVS were: patient rejection to the procedure, low catheterization rate in the center and unilateral disease based on CT/MRI. The overall success rate was 44.4% (the left adrenal vein was properly canulated in 77.8% and the right adrenal vein in 48.4%). Only 3 patients experienced minor complications. In the 45 patients with unilateral disease according to AVS, CT/MRI indicated bilateral disease or normal adrenal glands in 17. In the 23 patients with bilateral disease, CT/MRI indicated unilateral disease in 14. However, no significant differences were observed in biochemical response (P = 0.051) and hypertension resolution (P = 0.150) between patients who underwent surgery based on CT/MRI results and those who underwent surgery based on AVS results.

CONCLUSION

In our setting, AVS is still an underused technique in patients with PA. The low experience and success rate in AVS partially justify these results. More training for providers and patients needs to be done to include appropriate well performed AVS in the diagnosis algorithm of PA.

Machine learning approach to predict subtypes of primary aldosteronism is helpful to estimate indication of adrenal vein sampling

INTRODUCTION

Primary aldosteronism (PA) is a common disease. Especially in unilateral PA (UPA), the risk of cardiovascular disease is high and proper localization is important. Adrenal vein sampling (AVS) is commonly used to localize PA, but its availability is limited. Therefore, it is important to predict the unilateral or bilateral PA and to choose the appropriate cases for AVS or watchful observation.

AIM

The purpose of this study is to develop a model using machine learning to predict bilateral or unilateral PA to extract cases for AVS or watchful observation.

METHODS

We retrospectively analyzed 154 patients diagnosed with PA and who underwent AVS at our hospital between January 2010 and June 2021. Based on machine learning, we determined predictors of PA subtypes diagnosis from the results of blood and loading tests.

RESULTS

The accuracy of the machine learning was 88% and the top predictors of the UPA were plasma aldosterone concentration after the saline infusion test, aldosterone to renin ratio after the captopril challenge test, serum potassium and aldosterone-to-renin ratio. By using these factors, the accuracy, sensitivity, specificity and the area under the curve (AUC) were 91%, 70%, 99% and 0.91, respectively. Furthermore, we examined the surgical outcomes of UPA and found that the group diagnosed as unilateral by the predictors showed improvement in clinical findings, while the group diagnosed as bilateral by the predictors showed no improvement.

CONCLUSION

Our predictive model based on machine learning can support to choose the performance of adrenal vein sampling or watchful observation.

Recent Advances in the Clinical Application of Adrenal Vein Sampling

We reviewed clinical research investigating the applications of adrenal vein sampling (AVS). AVS could be applied not only to primary aldosteronism (PA) but also to other endocrine diseases, such as adrenocorticotropic hormone (ACTH) independent Cushing syndrome (AICS) and hyperandrogenemia (HA). However, the AVS protocol requires improvements to increase its success rate. Using the computed tomography image fusion, coaxial guidewire technique, and fast intraprocedural cortisol testing (CCF) technique could improve the success rate of catheterization in AVS for PA. ACTH loading could be considered in medical centers with a low selectivity of AVS for PA but is not essential in those with mature AVS technology. The continuous infusion method should be recommended for ACTH stimulation in AVS for PA to reduce adverse events. AVS has not been routinely recommended before management decisions in AICS, but several studies verified that AVS was useful in finding out the source of excess cortisol, especially for distinguishing unilateral from bilateral disease. However, it is necessary to reassess the results of AVS in AICS with the use of reference hormones to fully normalize cortisol levels. In addition, it is essential to determine the optimal model that combines AVS results and mass size to guide the selection of surgical plans, including identifying the dominant gland and presenting the option of staged adrenalectomy, to minimize the impact of bilateral resection. For HA, AVS combined with ovarian intravenous sampling to locate excess androgens could be considered when imaging results are equivocal.

Adrenal venous sampling in the diagnostic workup of primary aldosteronism

Primary aldosteronism (PA) is the primary cause of secondary hypertension. The prevalence of PA has probably been underestimated in the past and recent studies suggest that PA could be present in up to 10% of patients suffering from hypertension. Aldosterone excess in PA can be caused by unilateral adrenal disease, usually adrenal adenoma, or bilateral adrenal hyperplasia. Differentiation between unilateral and bilateral disease is clinically important as the former can effectively be treated by removal of the affected adrenal. CT or MRI cannot reliably distinguish unilateral from bilateral disease. Therefore, adrenal vein sampling (AVS) is an important step of the diagnostic work-up in patients with PA. Current guidelines recommend PA in virtually all patients with biochemically diagnosed PA who would undergo adrenal surgery if unilateral PA was diagnosed. In this narrative review, we give an overview of the current technique used for AVS with a focus on the experience with this technique at the University Hospital Basel, Switzerland.

Diagnosis of primary hyperaldosteronism

Primary aldosteronism (PA) is the most common cause of secondary arterial hypertension. Moreover, it is associated with a higher cardio-metabolic risk than the observed in patients with essential arterial hypertension (EHT). Therefore, a high index of clinical suspicion for PA is mandatory. If an elevated aldosterone/renin ratio is confirmed, confirmatory tests should be performed, with the exception in those patients with florid PA, with, with spontaneous hypokalaemia, plasma aldosterone > 20 ng/dL and suppressed renin, in whom this step would not be strictly necessary. Intravenous saline infusion test or captopril test are the commonly used confirmatory tests. The last step in the diagnosis of PA is the localization study, being the computerized axial tomography (CT) of the adrenal glands the initial test of choice, and adrenal venous sampling (AVS), the definitive localization test in most cases. This review summarizes the available data about the diagnosis of PA, from screening to confirmatory study and localization.

Diagnosis and treatment of primary aldosteronism

Primary aldosteronism is a common cause of secondary hypertension associated with excess cardiovascular morbidities. Primary aldosteronism is underdiagnosed because it does not have a specific, easily identifiable feature and clinicians can be poorly aware of the disease. The diagnostic investigation is a multistep process of screening, confirmatory testing, and subtype differentiation of unilateral from bilateral forms for therapeutic management. Adrenal venous sampling is key for reliable subtype identification, but can be bypassed in patients with specific characteristics. For unilateral disease, surgery offers the possibility of cure, with total laparoscopic unilateral adrenalectomy being the treatment of choice. Bilateral forms are treated mainly with mineralocorticoid receptor antagonists. The goals of treatment are to normalise both blood pressure and excessive aldosterone production, and the primary aims are to reduce associated comorbidities, improve quality of life, and reduce mortality. Prompt diagnosis of primary aldosteronism and the use of targeted treatment strategies mitigate aldosterone-specific target organ damage and with appropriate patient management outcomes can be excellent. Advances in molecular histopathology challenge the traditional concept of primary aldosteronism as a binary disease, caused by either a unilateral aldosterone-producing adenoma or bilateral adrenal hyperplasia. Somatic mutations drive autonomous aldosterone production in most adenomas. Many of these same mutations have been identified in nodular lesions adjacent to an aldosterone-producing adenoma and in patients with bilateral disease. In addition, germline mutations cause rare familial forms of aldosteronism (familial hyperaldosteronism types 1-4). Genetic testing for inherited forms in suspected cases of familial hyperaldosteronism avoids the burdensome diagnostic investigation in positive patients. In this Review, we discuss advances and future management approaches in the diagnosis of primary aldosteronism.

Radiological characteristics and diagnostic impact of duplicated right adrenal veins on adrenal venous sampling in primary aldosteronism

PURPOSE

We aimed to analyze the prevalence and radiological characteristics of duplicated right adrenal veins (DRAVs) and evaluate the diagnostic impact of adrenal venous sampling (AVS) in primary aldosteronism.

METHODS

DRAVs were retrospectively identified among patients who underwent segmental AVS between April 2017 and March 2020. DRAVs were defined as main or accessory according to the drainage area. The diameter, position, hormone levels, and treatment plan based on AVS were compared between main and accessory RAVs, using the Wilcoxon rank-sum test.

RESULTS

Fourteen of 432 patients (3.2%) were diagnosed with DRAVs. On venography, the mean diameters of the main and accessory side were 3±0.63 mm and 2.1±0.41 mm, respectively, and were significantly different (p < 0.001). The mean relative position in craniocaudal direction of main and accessory veins from the adrenal caudal edge on computed tomography was 65.5%±16.0%, and 48.1%±16.8%, respectively, which was significantly different (p = 0.007). The left-right positions and hormone levels were not significantly different. Based on conventional AVS, the treatment plan between DRAVs was not changed in six of eight patients, but changed from surgery to medication in two patients with right aldosterone-producing adenoma (APA)/microadenoma based on segmental AVS findings.

CONCLUSION

DRAVs, in which the main RAV was thicker and more cranially located than the accessory RAV were rare. Depending on blood sampled from either of DRAVs, the diagnosis made through conventional AVS might change treatment approach from surgery to medication, especially with right APA. Hence, their identification is important to make an accurate subtyping by AVS.

Primary Hyperaldosteronism: Approach to Diagnosis and Management

Hyperaldosteronism is a relatively more common disorder than previously recognized. Patients with hyperaldosteronism are at high risk for cardiovascular events. Patients suspected of having hyperaldosteronism should undergo initial screening and subsequent confirmatory testing to establish a biochemical diagnosis. Although adrenal computed tomography/magnetic resonance imaging scans often define a disease's subtype, adrenal vein sampling, in order to determine lateralization, may be necessary in some patients who are surgical candidates. Medical therapy using optimal doses of mineralocorticoid receptor antagonists can control symptoms and normalize plasma renin activity. The long-term outcome of patients treated with either surgical or optimal medical therapy appears similar.

Determination of adrenal hypersecretion in primary Aldosteronism without aldosterone-production adenomas

BACKGROUND

Primary aldosteronism (PA) is highly prevalent in hypertensive population. Adrenal vein sampling (AVS) is the only procedure to assess adrenal aldosterone hypersecretion in PA. PA patients without aldosterone-producing adenomas (APA) frequently have unilateral aldosterone hypersecretion (UAH). These patients could bear inappropriate adrenalectomy without AVS. This study aims to identify which clinical characteristics should be recommended to perform AVS in these PA patients.

METHODS

This study was performed from January 2018 to July 2019 at a center for hypertension and metabolic diseases. Adrenal computed tomography (CT) scan, biochemical evaluation, and AVS were performed.

RESULTS

Total 141 patients were included in this study. Aldosterone to renin ratio (ARR) after confirmatory test is highly associated with adrenal laterality. The specificity of ARR > 10 (ng/dL)/(mU/L) after confirmatory test is 100%. After confirmatory test, patients with ARR > 10 (ng/dL)/(mU/L) had higher plasma aldosterone concentration and incidences of ischemic heart diseases and renal damage(p < 0.05).

CONCLUSIONS

After confirmatory tests, ARR > 10 (ng/dL)/(mU/L) indicates adrenal laterality, with increasingly cardiorenal damage in PA patients without APA. Thus, AVS should be recommended in these patients before surgery.

TRIAL REGISTRATION

NCT03398785 , Date of Registration: December 24, 2017.

Approach to the Patient with Primary Aldosteronism: Utility and Limitations of Adrenal Vein Sampling

Several studies over the past 3 decades document a higher prevalence of primary aldosteronism (PA) among hypertensive patients than generally presumed. PA exists as a spectrum from mild to severe aldosterone excess. Although a variety of PA subtypes exist, the 2 most common are aldosterone-producing adenomas (APAs) and bilateral hyperaldosteronism (BHA). The distinction is important, because APA-and other subtypes, with aldosterone production mostly from 1 adrenal-can be cured surgically, and BHA should be treated medically with mineralocorticoid-receptor antagonists (MRAs). The major shortcomings in the tailored management of patients with possible PA are the low rates of screening for case identification and the expensive and technically challenging imaging and interventional procedures required to distinguish APA from BHA, especially adrenal vein sampling (AVS). When AVS identifies an APA and allows the patient to be cured surgically, the procedure is of great value. In contrast, the patient with BHA is treated with MRA whether AVS is performed or not. Consequently, it is prudent to gauge how likely it is to benefit from imaging and AVS in each case prior to embarking on these studies. The explosion of information about PA in the past decade, including predictors of APA and of surgical benefit, are useful in limiting the evaluation for some patients with a positive PA screening test. This article will review our suggestions for approaching these patients in a pragmatic style, recognizing the limitations to even the best resources and facilities.

Recent Development toward the Next Clinical Practice of Primary Aldosteronism: A Literature Review

For the last seven decades, primary aldosteronism (PA) has been gradually recognized as a leading cause of secondary hypertension harboring increased risks of cardiovascular incidents compared to essential hypertension. Clinically, PA consists of two major subtypes, surgically curable and uncurable phenotypes, determined as unilateral or bilateral PA by adrenal venous sampling. In order to further optimize the treatment, surgery or medications, diagnostic procedures from screening to subtype differentiation is indispensable, while in the general clinical practice, the work-up rate is extremely low even in the patients with refractory hypertension because of the time-consuming and labor-intensive nature of the procedures. Therefore, a novel tool to simplify the diagnostic flow has been recently in enormous demand. In this review, we focus on recent progress in the following clinically important topics of PA: prevalence of PA and its subtypes, newly revealed histopathological classification of aldosterone-producing lesions, novel diagnostic biomarkers and prediction scores. More effective strategy to diagnose PA based on better understanding of its epidemiology and pathology should lead to early detection of PA and could decrease the cardiovascular and renal complications of the patients.

Adrenal Venous Sampling-Guided Adrenalectomy Rates in Primary Aldosteronism: Results of an International Cohort (AVSTAT)

CONTEXT

Adrenal venous sampling (AVS) is the current criterion standard lateralization technique in primary aldosteronism (PA). Japanese registry data found that 30% of patients with unilateral PA did not undergo adrenalectomy, but the reasons for this and whether the same pattern is seen internationally are unknown.

OBJECTIVE

To assess the rate of AVS-guided adrenalectomy across an international cohort and identify factors that resulted in adrenalectomy not being performed in otherwise eligible patients.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective, multinational, multicenter questionnaire-based survey of management of PA patients from 16 centers between 2006 and 2018.

MAIN OUTCOME MEASURES

Rates of AVS implementation, AVS success rate, diagnosis of unilateral PA, adrenalectomy rate, and reasons why adrenalectomy was not undertaken in patients with unilateral PA.

RESULTS

Rates of AVS implementation, successful AVS, and unilateral disease were 66.3%, 89.3% and 36.9% respectively in 4818 patients with PA. Unilateral PA and adrenalectomy rate in unilateral PA were lower in Japanese than in European centers (24.0% vs 47.6% and 78.2% vs 91.4% respectively). The clinical reasoning for not performing adrenalectomy in unilateral PA were more likely to be physician-derived in Japan and patient-derived in Europe. Physician-derived factors included non-AVS factors, such as good blood pressure control, normokalemia, and the absence of adrenal lesions on imaging, which were present before AVS.

CONCLUSION

Considering the various unfavorable aspects of AVS, stricter implementation and consideration of surgical candidacy prior to AVS will increase its diagnostic efficiency and utility.

Feasibility and effectiveness of a single-catheter approach for adrenal vein sampling in patients with primary aldosteronism

BACKGROUND

Adrenal vein sampling (AVS) is the preferred method for subtyping patients with primary aldosteronism, while the procedure is technically challenging. This study evaluated the feasibility and effectiveness of a single-catheter approach for AVS.

METHODS

A retrospective analysis of 106 consecutive patients who underwent AVS was performed to determine the procedural success and complication rates. Bilateral AVS procedures were performed using a single 5-Fr Tiger catheter with repeated manual reshaping.

RESULTS

We successfully advanced the catheter into the bilateral adrenal veins of all patients and reached a 90.6% procedural success rate of AVS. The procedural period was 33.0 ± 8.2 min, the fluoroscopy period was 5.8 ± 1.7 min, and the diagnostic contrast used was 17.3 ± 5.5 ml. Only one patient (0.9%) had a hematoma at the femoral puncture site. No other complications were observed. The operation period gradually shortened as the cumulative number of operations increased. The number of procedures required to overcome the learning curve was about 33 cases.

CONCLUSIONS

The single-catheter approach is feasible and effective for AVS. Moreover, this approach required a relatively short learning curve for an inexperienced trainee.

Should Adrenal Venous Sampling Be Performed in PA Patients Without Apparent Adrenal Tumors?

INTRODUCTION

Some aldosterone-producing micro-adenomas cannot be detected through image inspection. Therefore, adrenal venous sampling (AVS) is often performed, even in primary aldosteronism (PA) patients who have no apparent adrenal tumors (ATs) on imaging. In most of these cases, however, the PA is bilateral.

OBJECTIVE

To clarify the clinical need for AVS in PA patients without apparent ATs, taking into consideration the rates of adrenalectomy.

METHODS

This is a retrospective cross-sectional study assessing 1586 PA patients without apparent ATs in the multicenter Japan PA study (JPAS). We analyzed which parameters could be used to distinguish unilateral PA patients without apparent ATs from bilateral patients. We also analyzed the prevalences of adrenalectomy in unilateral PA patients.

RESULTS

The unilateral subtype without an apparent AT was diagnosed in 200 (12.6%) of 1586 PA patients. Being young and female with a short hypertension duration, normokalemia, low creatinine level, low plasma aldosterone concentration, and low aldosterone-to-renin ratio (ARR) was significantly more common in bilateral than unilateral PA patients. If PA patients without apparent ATs were female and normokalemic with a low ARR (<560 pg/ml per ng/ml/h), the rate of unilateral PA was only 5 (1.1%) out of 444. Moreover, 77 (38.5%) of the 200 did not receive adrenalectomy, despite being diagnosed with the unilateral subtype based on AVS.

CONCLUSION

The low prevalence of the unilateral subtype in PA patients without apparent ATs suggests AVS is not indicated for all of these patients. AVS could be skipped in female normokalemic PA patients without apparent ATs if their ARRs are not high. However, AVS should be considered for male hypokalemic PA patients with high ARRs because the rates of the unilateral subtype are high in these patients.

Update: Selective adrenal venous sampling (AVS) - Indication, technique, and significance

BACKGROUND

 Primary aldosteronism (PA) is the most common detectable cause of secondary hypertension. The majority of patients have either an adrenal aldosterone-producing adenoma (APA) or bilateral adrenal hyperplasia (BAH) demanding different therapeutic approaches. Screening tests and imaging cannot reliably distinguish between a unilateral or bilateral PA.

METHODS

 This review article gives an overview concerning etiology, diagnostics, and therapeutic options of PA, and reviews the indication, the technique, and relevance of selective adrenal venous sampling (AVS) in the context of the current literature and the authors' experience.

RESULTS

 AVS can verify or exclude a unilaterally dominated secretion with a high success rate. Patients with PA and a unilateral APA can be treated curatively by adrenalectomy.

CONCLUSIONS

 AVS is an established diagnostic examination for differentiation of unilateral from bilateral adrenal disease in patients with PA.

KEY POINTS

· Selective adrenal venous sampling (AVS) is a safe, reliable, and minimally invasive method to detect a unilateral or bilateral adrenal adrenal gland disease.. · Verification of lateralization by AVS has direct therapeutic relevance for patients with primary aldosteronism (PA).. · AVS can be performed with low radiation exposure, without contrast medium, and with a high success rate when performed by an experienced interventional radiologist..

CITATION FORMAT

· Loberg C, Antoch G, Stegbauer J et al. Update: Selective adrenal venous sampling (AVS) - Indication, technique, and significance. Fortschr Röntgenstr 2021; 193: 658 - 666.

The diagnostic accuracy of adjusted unconventional indices for adrenal vein sampling in the diagnosis of primary aldosteronism subtypes

OBJECTIVE

Simple unconventional indices did not demonstrate a satisfactory accuracy for diagnosing unilateral primary aldosteronism when adrenal vein sampling is not bilaterally selective. This study aimed to evaluate the reliability of clinical/imaging-corrected unconventional indices for adrenal vein sampling in predicting unilateral primary aldosteronism.

METHODS

Data of all consecutive patients with primary aldosteronism subtyped with adrenal vein sampling, referred to two Italian centers, were analyzed retrospectively. All patients with proved unilateral aldosterone hypersecretion underwent adrenalectomy.

RESULTS

Unilateral disease was diagnosed in 58 cases (54.2%) and idiopathic hyperaldosteronism in 49 individuals (45.8%). The monoadrenal index (aldosterone-to-cortisol ratio in the adrenal vein) showed high accuracy in predicting ipsilateral disease and moderate accuracy in predicting contralateral aldosterone hypersecretion. The monolateral index (aldosterone-to-cortisol ratio in the adrenal vein vs. peripheral blood) revealed moderate accuracy in predicting ipsilateral disease and high accuracy in predicting contralateral aldosterone hypersecretion. Lesion side- and hypokalemia-corrected ROC curves for these unconventional indices revealed a significant improvement in the reliability of predicting ipsilateral/contralateral disease, reaching high accuracy in all models. For an immediate clinical application of our results, the adjusted cut-offs were calculated, according to the Youden's criterion and to a pre-established specificity of 95%, for all possible combinations of lesion side at imaging and presence/absence of hypokalemia.

CONCLUSION

This study demonstrated the high diagnostic accuracy of clinical-/imaging-corrected unconventional indices for adrenal vein sampling in the diagnosis of primary aldosteronism subtypes and suggests the use of these adjusted indices to select patients for adrenalectomy when adrenal vein sampling is not bilaterally selective.

Treatment of primary hyperaldosteronism

Primary aldosteronism is associated with higher cardiovascular and renal morbidity and mortality than essential hypertension in age- and sex-matched patients with the same degree of blood pressure elevation. Therefore, it is essential to establish a specific treatment to avoid the deleterious effects of aldosterone excess. Although adrenalectomy is generally considered the treatment of choice in cases of primary aldosteronism due to unilateral disease, several aspects and circumstances should be taken into account that may make medical treatment more appropriate. Among them, in this review we mention the limited experience and efficacy, and the potential risks of adrenal vein sampling; the risks and low efficacy of adrenalectomy; the high safety and efficacy of medical treatment and some special situations such as primary aldosteronism during pregnancy, in patients of advanced age or hereditary forms of primary aldosteronism, in which medical treatment is considered especially indicated as the first line therapy. The main studies comparing medical and surgical treatment in primary aldosteronism are also discussed.

Subtype diagnosis, treatment, complications and outcomes of primary aldosteronism and future direction of research: a position statement and consensus of the Working Group on Endocrine Hypertension of the European Society of Hypertension

: Primary aldosteronism is a frequent cause of secondary hypertension requiring a specific pharmacological treatment with mineralocorticoid receptor antagonist or with unilateral adrenalectomy. These treatments have shown to reduce the excess of cardiovascular risk characteristically associated with this disease. In part I of this consensus, we discussed the procedures for the diagnosis of primary aldosteronism. In the present part II, we address the strategies for the differential diagnosis of primary aldosteronism subtypes and therapy. We also discuss the evaluation of outcomes and provide suggestions for follow-up as well as cardiovascular and metabolic complications specifically associated with primary aldosteronism. Finally, we analyse the principal gaps of knowledge and future challenges for research in this field.

Adrenal vein sampling for primary aldosteronism: a 15-year national referral center experience

Background

Adrenal vein sampling (AVS) is essential for diagnostics of primary aldosteronism, distinguishing unilateral from bilateral disease and determining treatment options. We reviewed the performance of AVS for primary aldosteronism at our center during first 15 years, comparing the initial period to the period after the introduction of a dedicated radiologist. Additionally, AVS outcomes were checked against CT findings and the proportion of operated patients with proven unilateral disease was estimated.

Patients and methods

A retrospective cross-sectional study conducted at the national endocrine referral center included all patients with primary aldosteronism who underwent AVS after its introduction in 2004 until the end of 2018. AVS was performed sequentially during Synacthen infusion. When the ratio of cortisol concentrations from adrenal vein and inferior vena cava was at least 5, AVS was considered successful.

Results

Data from 235 patients were examined (168 men; age 32–73, median 56 years; BMI 18–48, median 30.4 kg/ m²). Average number of annual AVS procedures increased from 7 in the 2004–2011 period to 29 in the 2012–2018 period (p < 0.001). AVS had to be repeated in 10% of procedures; it was successful in 77% of procedures and 86% of patients. The proportion of patients with successful AVS (92% in 2012–2018 vs. 66% in 2004–2011, p < 0.001) and of successful AVS procedures (82% vs. 61%, p < 0.001) was statistically significantly higher in the recent period.

Conclusions

Number of AVS procedures and success rate at our center increased over time. Introduction of a dedicated radiologist and technical advance expanded and improved the AVS practice.

Performance of the unilateral AV/IVC index in primary hyperaldosteronism subtype prediction: A validation study in a single tertiary centre

BACKGROUND

Failure of cannulation of the right adrenal vein is frequent during AVS for investigation of primary aldosteronism (PA). The aldosterone:cortisol ratio of either adrenal vein compared with the inferior vena cava (AV/IVC index) has been proposed to differentiate between unilateral and bilateral disease, and aid in lateralization of unilateral disease.

METHODS

Sixty-two patients with unilateral or bilateral PA identified by either successful bilateral (45 patients) or unilateral (17 patients) adrenal vein cannulation, and with biochemical remission following surgery were enrolled into the analysis. The diagnostic performances of the previously identified AV/IVC index cut-offs of ≥5.5 to predict ipsilateral disease and ≤0.5 to predict contralateral disease were validated using data from the entire cohort.

RESULTS

Fifty-three patients had unilateral PA and 9 patients bilateral PA. The area under ROC curve (AUROC) of the AV/IVC cut-off ≤0.5 for identifying unilateral aldosterone secretion from the contralateral adrenal was 0.95 (95% CI; 0.88-0.99), whereas the AUROC of the AV/IVC cut-off ≥5.5 for identifying unilateral aldosterone secretion from ipsilateral adrenal was 0.96 (95% CI; 0.92-0.99). The AV/IVC index cut-off value of 0.5 had 93% sensitivity and 91% specificity, and the AV/IVC index cut-off value of 5.5 had 21% sensitivity and 100% specificity. The optimal AV/IVC cut-offs to achieve 100% specificity for our cohort were >2.4 and <0.1 to predict ipsilateral and contralateral disease.

CONCLUSION

Our data confirm that the AV/IVC index is a potential tool for subtype classification and lateralization in patients with PA in the setting of failed bilateral, but successful unilateral, adrenal vein cannulation during AVS.

10 good reasons why adrenal vein sampling is the preferred method for referring primary aldosteronism patients for adrenalectomy

: Nowadays most patients diagnosed with surgically curable primary aldosteronism have small or micro aldosterone-producing adenoma or unilateral micronodular hyperplasia, which are undetectable with available imaging technologies. Therefore, a negative imaging test by no means excludes unilateral primary aldosteronism. Moreover, about 10% of the subjects above the age of 35 years have nonfunctioning adrenal tumors, regardless of being hypertensive or not, with a prevalence that raises with aging. Hence, the finding of an adrenal mass at imaging does not reliably detect the culprit of primary aldosteronism. On the other hand, when primary aldosteronism patients are selected for adrenalectomy on the basis of demonstration of lateralized aldosterone excess at adrenal vein sampling (AVS), close to 100% are biochemically cured from the hyperaldosteronism, about 45% are cured of arterial hypertension and an additional 52% are markedly improved in terms of blood pressure control. By contrast, patients referred for surgery based on imaging alone often fail to reach these successful outcomes, indicating that surgery was unnecessary or, even worse, performed on the wrong side. For these reasons, and because of the lack of accurate and widely available alternative methods, all current guidelines recommend that AVS be offered to all primary aldosteronism patients with only few exceptions, mainly in patients unable or unwilling to undergo surgery and those with germ-line mutations causing familial primary aldosteronism. The main argument against systematic use of AVS entails its suboptimal performance, partly justified by its intrinsic technical difficulty, and its limited availability. This led to propose skipping AVS strategies for predicting surgically curable primary aldosteronism, but success has been inconsistent. The most urgent standing issue is, therefore, not to find loopholes to avoid AVS, but rather to improve its use, which means improving the rate of AVS success, through formal training of interventionists, selection of appropriate cutoffs and exploitation of a standardized procedure.

Using microwave thermal ablation to develop a subtotal, cortical-sparing approach to the management of primary aldosteronism

Objective: To investigate the feasibility and efficacy of localized, subtotal, cortical-sparing microwave thermal ablation (MTA) as a potential curative management for primary aldosteronism. The study investigated with equal importance the selected ablation of small volumes of adrenal cortex while sparing adjacent cortex. Method: An in-vivo study was carried out in swine (n = 8) where MTA was applied under direct visualization, to the adrenal glands at 45 W or 70 W for 60 s, using a lateral, side-firing probe and a non-penetrative approach. Animals were survived for 48 h post-procedurally. Animals were investigated for markers of histological, immunohistochemical and biochemical evidence of adrenal function and adrenal damage by assessing samples drawn intra-operatively and at the time of euthanasia. Results: Selected MTA (70 W for 60 s) successfully ablated small adrenocortical volumes (∼0.8 cm³) characterized by coagulative necrosis and abnormal expression of functional markers (CYP11B1 and CYP17). Non-ablated, adjacent cortex was not affected and preserved normal expression of functional markers, without increased expression of markers of heat damage (HSP-70 and HMGB-1). Limited adrenal medullary damage was demonstrated histologically, clinically and biochemically. Conclusion: MTA offers potential as an efficient methodology for delivering targeted subtotal cortical-sparing adrenal ablation. Image-guided targeted MTA may also represent a safe future modality for curative management of PA, in the setting of both unilateral and bilateral disease.

Anticoagulation-induced unilateral adrenal haemorrhage and pseudoaneurysm

Spontaneous unilateral adrenal haemorrhage (AH) is extremely rare. Its presentation is usually non-specific and requires a high degree of suspicion as it is associated with high morbidity and mortality if diagnosis is delayed. Hereby, we present a case of 67-year-old man with significant cardiac history presented with right-sided chest pain and non-specific abdominal pain. He was previously treated for non-ST elevation myocardial infarction 5 days ago prior to the current presentation. CT scan of abdomen and pelvis demonstrated a right-sided active AH. The patient subsequently underwent digital subtraction angiography. Angio-embolisation was attempted for the pseudoaneurysm but failed due to spasm of the vessel. He was managed conservatively and discharged after clinical improvement. Clinic review 6 months later showed significant size reduction of the pseudoaneurysm.

Adrenal Venous Sampling: Where Do We Stand?

Adrenal venous sampling is the gold standard test to identify surgically curable primary aldosteronism, but it is markedly underused in clinical practice being perceived as a technically challenging and invasive procedure and, moreover, as difficult to interpret. This review provides updated information on current indications to adrenal venous sampling and how to perform and interpret adrenal venous sampling.

18-Oxocortisol Synthesis in Aldosterone-Producing Adrenocortical Adenoma and Significance of KCNJ5 Mutation Status

Peripheral 18-oxocortisol (18oxoF) level could contribute to the detection of aldosterone-producing adenoma (APA) in patients with primary aldosteronism. However, peripheral 18oxoF varies among such patients, which is a big drawback concerning its clinical application. We studied 48 cases of APA, 35 harboring KCNJ5 mutation, to clarify the significance of clinical and pathological parameters about peripheral 18oxoF. Peripheral 18oxoF concentration ranged widely from 0.50 to 183.13 ng/dL and correlated positively with intratumoral areas stained positively for steroidogenic enzymes ( P<0.0001). The peripheral 18oxoF level also correlated significantly with that of circulating aldosterone ( P<0.0001) but not with that of cortisol, a precursor of 18oxoF. However, a significant correlation was detected between peripheral 18oxoF and intratumoral glucocorticoids ( P<0.05). In addition, peripheral 18oxoF correlated positively with the number of hybrid cells double positive for 11β-hydroxylase and aldosterone synthase ( P<0.0001). Comparing between the cases with and those without KCNJ5 mutation, the KCNJ5-mutated group demonstrated a significantly higher concentration of peripheral 18oxoF (28.4±5.6 versus 3.0±0.9 ng/dL, P<0.0001) and a larger intratumoral environment including the hybrid cells ( P<0.001), possibly representing a deviation from normal aldosterone biosynthesis. After multivariate analysis, KCNJ5 mutation status turned out to be the most associated factor involved in 18oxoF synthesis in APA ( P<0.0001). Results of our present study first revealed that enhanced 18oxoF synthesis in APA could come from a functional deviation of aldosterone biosynthesis from the normal zona glomerulosa and the utility of peripheral 18oxoF measurement could be influenced by the prevalence of KCNJ5 mutation in an APA.

Steroid Profiling and Immunohistochemistry for Subtyping and Outcome Prediction in Primary Aldosteronism-a Review

PURPOSE OF REVIEW

Steroid profiling and immunohistochemistry are both promising new tools used to improve diagnostic accuracy in the work-up of primary aldosteronism (PA) and to predict treatment outcomes. Herein, we review the recent literature and present an outlook to the future of diagnostics and therapeutic decision-making in patients with PA.

RECENT FINDING

PA is the most common endocrine cause of arterial hypertension and unilateral forms of the disease are potentially curable by surgical resection of the overactive adrenal. Recent studies have shown that adrenal steroid profiling by liquid chromatography-tandem mass spectrometry (LC-MS/MS) can be helpful for subtyping unilateral and bilateral forms of PA, classifying patients with a unilateral aldosterone-producing adenoma (APA) according to the presence of driver mutations of aldosterone production in APAs, and potentially predicting the outcomes of surgical treatment for unilateral PA. Following adrenalectomy, immunohistochemistry of aldosterone synthase (CYP11B2) in resected adrenals is a new tool to analyze "functional" histopathology and may be an indicator of biochemical outcomes after surgery. Biochemical and clinical outcomes of therapy in PA vary widely among patients. Peripheral venous steroid profiling at baseline could improve diagnostic accuracy and help in surgical decision-making in cases of a suspected APA; results of "functional" histopathology could help determine which patients are likely to need close post-surgical follow-up for persistent aldosteronism.

Clinical Outcomes of 1625 Patients With Primary Aldosteronism Subtyped With Adrenal Vein Sampling

We sought to measure the clinical benefits of adrenal venous sampling (AVS), a test recommended by guidelines for primary aldosteronism (PA) patients seeking surgical cure, in a large registry of PA patients submitted to AVS. Data of 1625 consecutive patients submitted to AVS in 19 tertiary referral centers located in Asia, Australia, Europe, and North America were collected in a large multicenter international registry. The primary end points were the rate of bilateral success, ascertained lateralization of PA, adrenalectomy, and of cured arterial hypertension among AVS-guided and non AVS-guided adrenalectomy patients. AVS was successful in 80.1% of all cases but allowed identification of unilateral PA in only 45.5% by the criteria in use at each center. Adrenalectomy was performed in 41.8% of all patients and cured arterial hypertension in 19.6% of the patients, 2-fold more frequently in women than men (P<0.001). When AVS-guided, surgery provided a higher rate of cure of hypertension than when non-AVS-guided (40.0% versus 30.5%; P=0.027). Compared with surgical cases, patients treated medically needed more antihypertensive medications (P<0.001) and exhibited a higher rate of persistent hypokalemia requiring potassium supplementation (4.9% versus 2.3%; P<0.01). The low rate of adrenalectomy and cure of hypertension in PA patients seeking surgical cure indicates suboptimal AVS use, possibly related to issues in patient selection, technical success, and AVS data interpretation. Given the better outcomes of AVS-guided adrenalectomy, these results call for actions to improve the diagnostic use of this test that is necessary for detection of surgical PA candidates. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT01234220.

A Case of Primary Aldosteronism Due to A Primary Adrenal Adenoma Diagnosed by Segmental Adrenal Venous Sampling (S-AVS) Using a Modified Catheter System and Lateral Cine Angiography

BACKGROUND Before partial adrenalectomy for primary aldosteronism due to a primary adrenal adenoma, the aldosterone-producing tumor can be localized by segmental adrenal vein sampling (S-AVS). Cardiologists, who regularly perform percutaneous coronary intervention (PCI), or coronary angioplasty with stent, may not be familiar with the technique of S-AVS. A case of the use of S-AVS is reported in a patient who presented with primary aldosteronism and a right adrenal adenoma. CASE REPORT A 44-year-old man with a history of hypertension presented with a man in the posterior part of the right adrenal gland. He had hypokalemia, and a high plasma aldosterone concentration/plasma renin activity ratio. A captopril stress test confirmed the diagnosis of primary aldosteronism. Pre-operative S-AVS was performed using a microwire and microcatheter, which were advanced into the segmental adrenal vein using a 6.5 French guiding catheter and a Y-shaped connector, under biplane cine angiography guidance. S-AVS showed a high plasma aldosterone concentration in the right superior tributary adrenal vein draining the adrenal mass. Right partial adrenalectomy was performed. Postoperatively, the patient's blood pressure and plasma aldosterone levels normalized. CONCLUSIONS S-AVS can be performed relatively easily before partial adrenalectomy using a catheter system with biplane cine angiography, which is a technique that is familiar to cardiologists.

Diagnosis and treatment of primary aldosteronism: practical clinical perspectives

Primary aldosteronism (PA), the most common form of secondary hypertension, can be either surgically cured or treated with targeted pharmacotherapy. PA is frequently undiagnosed and untreated, leading to aldosterone-specific cardiovascular morbidity and nephrotoxicity. Thus, clinicians should perform case detection testing for PA at least once in all patients with hypertension. Confirmatory testing is indicated in most patients with positive case detection testing results. The next step is to determine whether patients with confirmed PA have a disease that can be cured with surgery or whether it should be treated medically; this step is guided by computed tomography scan of the adrenal glands and adrenal venous sampling. With appropriate surgical expertise, laparoscopic unilateral adrenalectomy is safe, efficient and curative in patients with unilateral adrenal disease. In patients who have bilateral aldosterone hypersecretion, the optimal management is a low-sodium diet and lifelong treatment with a mineralocorticoid receptor antagonist administered at a dosage to maintain a high-normal serum potassium concentration without the aid of oral potassium supplements.

Development of [18F]FAMTO: A novel fluorine-18 labelled positron emission tomography (PET) radiotracer for imaging CYP11B1 and CYP11B2 enzymes in adrenal glands

INTRODUCTION

Primary aldosteronism accounts for 6-15% of hypertension cases, the single biggest contributor to global morbidity and mortality. Whilst ~50% of these patients have unilateral aldosterone-producing adenomas, only a minority of these have curative surgery as the current diagnosis of unilateral disease is poor. Carbon-11 radiolabelled metomidate ([11C]MTO) is a positron emission tomography (PET) radiotracer able to selectively identify CYP11B1/2 expressing adrenocortical lesions of the adrenal gland. However, the use of [11C]MTO is limited to PET centres equipped with on-site cyclotrons due to its short half-life of 20.4 min. Radiolabelling a fluorometomidate derivative with fluorine-18 (radioactive half life 109.8 min) in the para-aromatic position ([18F]FAMTO) has the potential to overcome this disadvantage and allow it to be transported to non-cyclotron-based imaging centres.

METHODS

Two strategies for the one-step radio-synthesis of [18F]FAMTO were developed. [18F]FAMTO was obtained via radiofluorination via use of sulfonium salt (1) and boronic ester (2) precursors. [18F]FAMTO was evaluated in vitro by autoradiography of pig adrenal tissues and in vivo by determining its biodistribution in rodents. Rat plasma and urine were analysed to determine [18F]FAMTO metabolites.

RESULTS

[18F]FAMTO is obtained from sulfonium salt (1) and boronic ester (2) precursors in 7% and 32% non-isolated radiochemical yield (RCY), respectively. Formulated [18F]FAMTO was obtained with >99% radiochemical and enantiomeric purity with a synthesis time of 140 min from the trapping of [18F]fluoride ion on an anion-exchange resin (QMA cartridge). In vitro autoradiography of [18F]FAMTO demonstrated exquisite specific binding in CYP11B-rich pig adrenal glands. In vivo [18F]FAMTO rapidly accumulates in adrenal glands. Liver uptake was about 34% of that in the adrenals and all other organs were <12% of the adrenal uptake at 60 min post-injection. Metabolite analysis showed 13% unchanged [18F]FAMTO in blood at 10 min post-administration and rapid urinary excretion. In vitro assays in human blood showed a free fraction of 37.5%.

CONCLUSIONS

[18F]FAMTO, a new 18F-labelled analogue of metomidate, was successfully synthesised. In vitro and in vivo characterization demonstrated high selectivity towards aldosterone-producing enzymes (CYP11B1 and CYP11B2), supporting the potential of this radiotracer for human investigation.

Update in adrenal venous sampling for primary aldosteronism

PURPOSE OF REVIEW

Current guidelines recommend adrenal venous sampling (AVS) to identify the surgically curable causes of hyperaldosteronism. In contrast with this recommendation, AVS remains markedly underutilized in clinical practice, which leads to deny curative adrenalectomy, to many patients with primary aldosteronism. The purpose of this review is to challenge the views that AVS is a technically challenging, invasive and risky procedure, which moreover, is difficult to interpret.

RECENT FINDINGS

Several studies, including a large international survey on how AVS is being performed and used at major referral centres worldwide the AVIS-1 Study - and a randomized clinical trial comparing and AVS and a computed tomography based strategy, will be examined.

SUMMARY

The results of these studies have sound implications for clinical practice in that they allow to define what to do and what not to do for proper performance and interpretation of AVS and avoidance of the main concern, for example the risk of adrenal vein rupture.

Progress in the Management of Primary Aldosteronism

Primary aldosteronism (PA) is now considered as one of leading causes of secondary hypertension, accounting for 5-10% of all hypertensive patients and more strikingly 20% of those with resistant hypertension. Importantly, those with the unilateral disease could be surgically cured when diagnosed appropriately. On the other hand, only a very limited portion of those suspected to have PA has been screened, diagnosed, or treated to date. With current advancement in medical technologies and genetic research, expanding knowledge of PA has been accumulated and recent achievements have also been documented in the care of those with PA. This review is aimed to have focused description on updated topics of the following; importance of PA screening both in the general and specialized settings and careful interpretation of screening data, recent achievements in hormone assays and sampling methods and their clinical relevance, and expanding knowledge on PA genetics. Improvement in workup processes and novel treatment options, as well as better understanding of the PA pathogenesis based on genetic research, might be expected to result in increased cure and better care of the patients.

Persistent Primary Aldosteronism Despite Iatrogenic Adrenal Hemorrhage After Adrenal Vein Sampling

Before surgery for primary aldosteronism (PA), localization is evaluated with adrenal vein sampling (AVS). A 56-year-old Japanese woman had a right adrenal mass, hypokalemia, and a high aldosterone/renin ratio. Stress tests confirmed the diagnosis of PA. Subsequently, preoperative AVS was performed and right adrenal hemorrhage (AH) occurred unexpectedly. Because hypertension persisted, laparoscopic right adrenalectomy was performed. Postoperatively, the blood pressure was normalized. Pathological examination revealed an adrenal cortical adenoma largely unaffected by necrosis and hemorrhage. Previous reports have also indicated that AH may not ameliorate PA. We discussed the clinical progress of AH and the measures to prevent causing AH.

Management of primary aldosteronism in patients with adrenal hemorrhage following adrenal vein sampling: A brief review with illustrative cases

The authors describe the clinical investigation of two cases of primary aldosteronism with adrenal hemorrhage (AH) following adrenal vein sampling. A literature review was conducted regarding the medical management of primary aldosteronism in patients with AH following adrenal vein sampling. Guidelines on the management of primary aldosteronism with AH following adrenal vein sampling are lacking. The two patients were followed with serial imaging to document resolution of AH and treated medically with excellent blood pressure response. Resolution of AH was achieved, but a repeat adrenal vein sampling was deferred given the increased morbidity risk associated with a repeat procedure.

Subtype Diagnosis of Primary Aldosteronism: Is Adrenal Vein Sampling Always Necessary?

Aldosterone producing adenoma and bilateral adrenal hyperplasia are the two most common subtypes of primary aldosteronism (PA) that require targeted and distinct therapeutic approaches: unilateral adrenalectomy or lifelong medical therapy with mineralocorticoid receptor antagonists. According to the 2016 Endocrine Society Guideline, adrenal venous sampling (AVS) is the gold standard test to distinguish between unilateral and bilateral aldosterone overproduction and therefore, to safely refer patients with PA to surgery. Despite significant advances in the optimization of the AVS procedure and the interpretation of hormonal data, a standardized protocol across centers is still lacking. Alternative methods are sought to either localize an aldosterone producing adenoma or to predict the presence of unilateral disease and thereby substantially reduce the number of patients with PA who proceed to AVS. In this review, we summarize the recent advances in subtyping PA for the diagnosis of unilateral and bilateral disease. We focus on the developments in the AVS procedure, the interpretation criteria, and comparisons of the performance of AVS with the alternative methods that are currently available.

A Case of Adrenal Vein Sampling in Primary Aldosteronism With Homolateral Suppression

Context:

Adrenal venous sampling (AVS) is regarded as the gold standard for diagnosis of primary aldosteronism (PA) subtypes, although some authors have questioned its diagnostic accuracy and highlighted the lack of standardized procedure protocols and interpretation criteria for AVS. In particular, the usefulness of cosyntropin stimulation and benefit of superselective adrenal vein catheterization have been hotly debated.

Objective:

We report a case that highlights the potential pitfalls of superselective sampling and demonstrates a negligible effect of cosyntropin stimulation on aldosterone secretion in nonadenomatous adrenal tissue when an aldosterone-producing adenoma (APA) is present.

Intervention and Results:

A 38-year-old man with PA and a single right macroadenoma underwent AVS at our center. The procedure was performed both under basal conditions and during cosyntropin stimulation. Right adrenal vein angiography demonstrated two branches of the main adrenal vein trunk, one draining the nodule and one draining the right adrenal gland. Hormonal assays confirmed adrenal origin of left-sided and all right-sided samples, and were consistent with lateralization on the right side, with suppression of aldosterone secretion in the left adrenal gland and in the nonadenomatous right adrenal tissue. Cosyntropin-stimulated AVS results were similar to those of the unstimulated procedure.

Conclusions:

Cosyntropin stimulation does not significantly affect aldosterone secretion from nonadenomatous adrenal tissue when an APA is present and can therefore be used during AVS for PA. Superselective AVS should be performed with caution and interpreted by expert clinicians.

New Advances in the Diagnostic Workup of Primary Aldosteronism

Primary aldosteronism is an important and common cause of hypertension that carries a high burden of morbidity. Outcomes, however, are excellent if diagnosed and treated appropriately. The diagnostic workup for primary aldosteronism is complex and comprises three steps: (1) screening, (2) confirmatory testing, and (3) subtype differentiation. In this review, we discuss recent advances in the diagnostic workup for primary aldosteronism. The development of accurate mass spectroscopy-based assays for measuring aldosterone will lead to improved confidence in all diagnostic aspects involving measurement of aldosterone, and accurate measurement of angiotensin II may soon advance us beyond the measurement of renin. We now have a greater understanding of hormonal influences on the aldosterone/renin ratio, which are particularly important when screening premenopausal women or those taking estrogen-containing preparations. Confirmatory testing is important, but there are limitations to the commonly used methods that have recently become more apparent, with new approaches offering a way forward. Adrenal venous sampling (AVS) is a challenging procedure but is important for deciding on treatment options. Success rates may be improved by the use of Synacthen stimulation and of rapid intraprocedural measurement of cortisol. Better understanding of AVS interpretation criteria allows improved prognostication and aids treatment decisions. The use of labeled metomidate positron emission tomography computed tomography scanning may also offer an alternative to AVS in some units. Although the diagnostic approach to patients with primary aldosteronism remains a complex multistep process in which attention to detail is important, recent advances will improve patient care and outcomes.