Successful Adrenal Vein Sampling Research Articles

Diagnostic performance of the adrenal vein to inferior vena cava aldosterone ratio in classifying the subtype of primary aldosteronism.

Adrenal vein sampling (AVS) is the standard procedure for distinguishing unilateral primary aldosteronism (PA) from bilateral PA. In cases where only one adrenal vein is successfully cannulated, it has been suggested that subtype classification can be determined based on the ratio of the concentration of aldosterone between the adrenal vein and the inferior vena cava (AV/IVC index). However, diagnostic performance of the ipsilateral versus contralateral AV/IVC index in predicting lateralization has not been directly compared. In a retrospective cohort of 133 patients with confirmed PA who underwent successful AVS, the performance of the AV/IVC index to predict laterality was evaluated and the area under the receiver operating characteristic (AUROC) curves was calculated. In detecting left unilateral PA (n = 47), the AUROC of the right AV/IVC index (RAV/IVC) was significantly higher than the AUROC of the left AV/IVC (LAV/IVC) index (0.967 vs. 0.871, p = 0.008). In detecting right unilateral PA (n = 30), the AUROC of the LAV/IVC index tended to be higher than that of the RAV/IVC index, but the difference did not reach statistical significance (0.966 vs. 0.906, p = 0.08). In detecting left unilateral PA, the sensitivities of the RAV/IVC and LAV/IVC indices were 83% and 46%, respectively, while the specificities of both were above 90%. In detecting right unilateral PA, the sensitivities of the LAV/IVC and RAV/IVC indices were 80% and 43%, respectively, while the specificities of both were above 90%. The AV/IVC index has superior diagnostic performance in detecting contralateral unilateral PA compared to ipsilateral unilateral PA.

Role of adrenal venous sampling in the differential diagnosis and treatment protocol of ACTH-independent Cushing's syndrome with bilateral adrenal lesions.

The diagnosis and management of adrenocorticotropic hormone-independent Cushing's syndrome (AICS) with bilateral adrenal lesions remain challenging. Some studies have explored the value of adrenal vein sampling (AVS) in patients with AICS; however, more investigations are needed to assess its benefits for diagnosis and treatment planning in this population. Thirteen patients with clinical, biochemical and imaging evidence of AICS with bilateral adrenal lesions underwent AVS in our department from 2017-2022 were recruited. Only the data from nine patients for whom AVS succeeded were finally included in this study and further analyzed. Blood samples were successfully collected from both adrenal veins (AV) and inferior vena cava (IVC) in these nine patients, and the levels of plasma total cortisol (PTC) and plasma aldosterone concentrations (PAC) were measured. The ratio of the PAC of the AV to the IVC was calculated, and the PTC to PAC ratios were compared between AV. The surgical strategy was chosen according to the results of AVS. Postoperative histology and immunohistochemistry of the adrenal tissues were performed. The prognosis was evaluated based on the improvement of clinical symptoms and biochemical parameters (including PTC and ACTH measurements). Patients with AICS were clinically diagnosed based on clinical signs, results of functional tests and the presence of bilateral adrenal lesions as observed on computed tomography imaging. An AV to IVC PAC ratio greater than 2 confirmed successful AVS. The PTC to PAC ratio (high side to low side) was greater than 2 in four patients, and less than 2 in five patients. The postoperative pathological results were consistent with clinical diagnosis and AVS. During the mean follow-up of 33 months, all nine patients achieved varying degrees of clinical improvement. Our study showed that AVS helped to distinguish unilateral and bilateral lesions, identify the laterality of the autonomous hypercortisolism, and improve therapeutic strategy selection in patients with AICS and bilateral adrenal lesions.

ODP586 Analysis of Adrenal Vein Sampling (AVS) Success: A Retrospective Study of Primary Aldosteronism Patients at the National University of Malaysia (UKM) Medical Center

Abstract Currently, the gold standard for identifying a unilateral Primary Aldosteronism (PA) is adrenal vein sampling (AVS), an invasive and technically challenging procedure. In this study, we aim to identify the clinical-laboratory characteristics associated with successful AVS, and clinical parameters associated with PA patients that had successful AVS (on 1st, 2nd, or 3rd attempt), or had rejected further attempts after a failed AVS attempt.100 records of AVS from eighty-three AVS patients conducted between 2015 and 2020 at the National University of Malaysia (UKM) Medical Centre, Kuala Lumpur, Malaysia were analysed retrospectively. Of the 83 PA patients studied, 47 were performed on men and 36 were on women. Variables significantly associated with patients who booked for a further attempt of AVS was having a serum aldosterone of <300pg/ml compared to those who rejected further attempts. There was also a trend for those who rejected further attempts to have a shorter duration of hypertension. Over one third of patient's have a failed AVS on 1st attempt and more than half do not wish to reattempt this invasive procedure. A biomarker for those that achieve complete cure should be identified to give incentives to the PA patients to proceed with AVS. Presentation: No date and time listed

Use the right kidney contour as a landmark in adrenal vein sampling.

Adrenal Vein Sampling (AVS) is the gold standard for categorizing primary aldosteronism (PA). However, catheterization of the right adrenal vein (RAV) is challenging due the small size and variable location. This study aims to explore the relationship between the RAV orifice and the right kidney contour (RKC) on fluoroscopy, thus evaluating the potential of use the RKC as an anatomic marker for localizing RAV. Imaging data of 107 PA patients with successful bilateral AVS were retrospectively analyzed. Based on the body mass index (BMI), all patients were divided into the Normal Group (BMI < 24 kg/m2), Overweight Group (24 kg/m2 ≤ BMI < 28 kg/m2) and Obese Group (BMI ≥ 28 kg/m2). At the anterior view, the height level of RAV orifice was determined relative to vertebral bodies and disks. The distance from the RAV orifice to the upper edge of RKC was measured manually. The RAV orifice height level was mainly distributed from vertebral T11 to T12 (90.6%), and tended to be higher in patients with a larger BMI. The mean distance from the RAV orifice to the upper edge of RKC was 13.9±7.8mm, and had no difference among Normal group (n = 53, 14.1±8.2mm), Overweight group (n = 39, 13.7±8.0mm), and Obese group (n = 15, 13.9±5.5mm) (p = 0.981). Based on these findings, the RKC might be used as a landmark for localizing RAV on fluoroscopy, which is conductive to narrow down the exploration range and increase the success rate of RAV catheterization.

Subtyping primary aldosteronism by inconclusive adrenal vein sampling: A derivation and validation study in a tertiary centre.

Indices based on aldosterone/cortisol (A/C) concentration in the successfully cannulated adrenal vein (AV) and in the inferior vena cava (IVC) (AV/IVC) appear to be possible markers to verify the subtype of primary aldosteronism (PA) in the case of inconclusive results of adrenal vein sampling (AVS). The variability of results in previous studies encouraged us to calculate AV/IVC and adrenal A/C cutoff values that could predict the aetiology of PA. This retrospective study included 96 patients who underwent AVS due to PA between 2015 and 2020. The derivation cohort ultimately consisted of 60 patients with bilaterally successful AVS and a clear diagnosis of unilateral or bilateral disease. Receiver operating characteristic analysis was used to find the optimal A/C and AV/IVC cutoff values predicting the subtype of PA. The validation cohort consisted of 11 patients with either unsuccessful cannulation or a borderline lateralization index (LI), those patients underwent adrenalectomy because their indices were suggestive of unilateral disease based on the derivation cohort data. The cutoff values of A/C ≤ 0.63 or AV/IVC ≤ 0.37 identified unaffected glands with a sensitivity of 91.2% and 97.1%, respectively, and a specificity of 90.7% and 88.4%, respectively. Unilateral ipsilateral gland involvement was characterized by A/C ≥ 3.5 or AV/IVC ≥ 3.4 with a corresponding specificity of 100%. All patients in the validation cohort achieved biochemical remission postoperatively. A/C and AV/IVC cutoff values could be a useful tool to determine the subtype of PA in patients with unilateral successful AVS as well as in patients with a borderline LI.

Successful Adrenal Vein Sampling Using Dexamethasone Premedication in Patients With Iodine Contrast Media Allergy.

ContextPreparation of patients with iodine contrast media (ICM) allergy who require adrenal vein sampling (AVS) to establish source of aldosterone excess of their confirmed primary aldosteronism (PA) is controversial. Usual premedication with high-dose prednisone can interfere with cortisol determinations, possibly altering the aldosterone to cortisol ratios for the identification of lateralized aldosterone excess.ObjectiveWe aimed to evaluate the efficacy and safety of premedication with high-dose dexamethasone to perform AVS in patients with ICM.MethodsOne hundred and seventy-seven consecutive patients with confirmed PA who underwent bilateral simultaneous basal and post-ACTH bolus AVS at our center between January 2010 and December 2020 were retrospectively analyzed for history of ICM allergy. A total of 7 patients (4%) with previous allergic reactions to ICM were prepared with 3 doses of 7.5 mg dexamethasone premedication rather than the usual 50 mg of prednisone.ResultsNo breakthrough allergic reactions were reported in the 7 patients. Despite adequate serum cortisol suppression following dexamethasone, the basal and post-ACTH selectivity index were respectively > 2 and > 5 bilaterally in all patients, confirming adequate cannulation of both adrenal veins. Four patients had lateralized ratios (A/C ratio > 2 basally and > 4 post-ACTH), while 3 had bilateral source during AVS study. In the 3 patients undergoing unilateral adrenalectomy for lateralized source and contralateral suppression and adequate follow-up data, cure of PA was achieved at mean 58 months postoperatively.ConclusionAVS using dexamethasone premedication is safe and accurate for diagnosing the source of aldosterone excess in patients with PA and ICM allergy.

Comparison of Cortisol, Androstenedione and Metanephrines to Assess Selectivity and Lateralization of Adrenal Vein Sampling in Primary Aldosteronism.

Success of adrenal vein sampling (AVS) is verified by the selectivity index (SI), i.e., by a step-up of cortisol levels between the adrenal vein and the infrarenal inferior vena cava samples, beyond a given cut-off. We tested the hypothesis that androstenedione, metanephrine, and normetanephrine, which have higher gradients than cortisol, could increase the rate of AVS studies judged to be bilaterally successful and usable for the clinical decision making. We prospectively compared within-patient, head-to-head, the selectivity index of androstenedione (SIA), metanephrine (SIM), and normetanephrine (SINM), and cortisol (SIC) in consecutive hypertensive patients with primary aldosteronism submitted to AVS. Main outcome measures were rate of bilateral success, SI values, and identification of unilateral PA. We recruited 136 patients (55 + 10 years, 35% women). Compared to the SIC, the SIA values were 3.5-fold higher bilaterally, and the SIM values were 7-fold and 4.4-fold higher on the right and the left side, respectively. With the SIA and the SIM the rate of bilaterally successful AVS increased by 14% and 15%, respectively without impairing the identification of unilateral PA. We concluded that androstenedione and metanephrine outperformed cortisol for ascertaining AVS success, thus increasing the AVS studies useable for the clinical decision making.

Limited diagnostic utility of partially successful adrenal vein sampling for primary aldosteronism subtyping.

Failure of adrenal vein sampling (AVS) due to difficult cannulation of the right adrenal vein (AV) frequently precludes subtyping of patients with primary aldosteronism (PA) before adrenalectomy. According to a recent study, lateralized PA could be accurately predicted from partial AVS data based on the gradient of the aldosterone-to-cortisol ratios (ACR) between left AV and inferior vena cava (IVC) (LAV/IVC index). We aimed to validate the diagnostic utility of this index for PA subtyping in our cohort. A retrospective cross-sectional study included all patients who underwent bilaterally successful AVS at our centre and were diagnosed with either bilateral PA according to AVS or with lateralized PA after successful adrenalectomy from November 2004 to the end of 2019. Final diagnoses were compared to originally suggested LAV/IVC index cut-offs of ≥ 5.5 for ipsilateral disease and of ≤ 0.5 for contralateral disease, respectively. The inclusion criteria were met in 168 patients: 46 women and 122 men, aged 54 years on average (range 32-72 years); 67 with lateralized and 101 with bilateral PA. LAV/IVC index using cut-offs of ≥ 5.5 or ≤ 0.5 anticipated ipsilateral (left lateralized) PA with a sensitivity of 32% and specificity of 97%, while a sensitivity of 47% and specificity of 95%, were found for contralateral (right lateralized) PA in our cohort. The overall inappropriate adrenalectomy rate was 29.7% (p = 0.314 for comparison between sides). When ascertaining ipsilateral disease (LAV/IVC index ≥ 5.5), 4 out of 16 patients (25%) would have been incorrectly sent to left adrenalectomy. Inappropriate right adrenalectomy would have occurred in 7 out of 21 patients (33.3%) when predicting contralateral disease (LAV/IVC index of ≤ 0.5). Thus, 11 patients with bilateral PA (6.5% of the entire cohort) would have been misclassified as lateralized PA and referred to surgery. Failed lateralization would have occurred in 61.2% of patients overall (53.3% for overlooked contralateral disease, 67.6% for missed ipsilateral disease; p = 0.723 for comparison between sides). Based on our cohort, we conclude that application of the suggested LAV/IVC index cut-offs did not predict lateralized PA with the high accuracy previously reported.

Laterality Diagnosis of Adrenal Vein Sampling for Primary Aldosteronism Using Aldosterone Alone

Background: In adrenal vein sampling (AVS) for primary aldosteronism (PA), cortisol concentration is used to determine successful AVS, and laterality diagnosis is performed using a combination of aldosterone and cortisol concentrations. In this study, we examined the comparison with the conventional method when AVS was determined by aldosterone alone. Subjects and methods: We studied the data from 277 patients with PA who underwent AVS in Sapporo City General Hospital from July 2007 to April 2020. The patients with autonomous cortisol production were excluded. Using the blood samples from adrenal veins and inferior vena cava (IVC) after ACTH stimulation, the predicting ability of the left and right ratio of aldosterone concentration (aldosterone ratio, AR) for lateralization Index (LI) was examined by Receiver operating characteristic (ROC) analysis. The predicting abilities of the ratio of aldosterone concentration between adrenal vein and IVC (aldosterone index, AI) and aldosterone concentration for selectivity index (SI) and contralateral ratio (CR) were also examined by ROC analysis. Results: Six samples (0.01%) with SI <5 after ACTH stimulation those were determined unsuccessful AVS. The results of the area under the curve (AUC) in ROC analysis of aldosterone concentration and AI for prediction of SI>5 was 0.998, 0.990, respectively, p=0.39. The optimal cut-off values of aldosterone concentration and AI for prediction successful AVS were 1700 pg/ml (sensitivity 99.5%, specificity 100%), 7.44 (sensitivity 94.0%, specificity 100%), respectively. Seventy-two patients (27.3%) had LI >4 who were diagnosed as unilateral aldosterone excess. AR had 0.94 of AUC for prediction of LR >4. The optimal cut-off value of AR was 3.53 (sensitivity 86.1%, specificity 94.8%). Eighty-two patients (31.1%) had unilateral CR<1. The AUC of aldosterone concentration and AI for prediction of CR<1 was 0.96, 0.98, respectively, p=0.07. The optimal cut-off values of aldosterone concentration and AI were 13600 pg/ml, 42, respectively. The sensitivity and the specificity at the optimal cut-off points of aldosterone concentration and AI were 91.5%, 91.5% and 91.5%, 94.8%, respectively. Conclusions: The determination of successful AVS and unilateral result in AVS can be predicted using aldosterone alone. It was suggested that AR is useful for tentative interpretation in the cases where the results of aldosterone were previously reported and lateralizing diagnosis of the cases with autonomous cortisol production.

External Validation of Prediction Models for Unilateral Primary Aldosteronism

Abstract Primary aldosteronism (PA) is the most common cause of remediable hypertension. Treatment is informed by establishing whether disease is unilateral (localized to one adrenal gland) or bilateral. Adrenalectomy is the guideline-recommended treatment of choice for unilateral PA. However, the currently recommended subtyping test, adrenal vein sampling (AVS), is often limited in accessibility. Thus, prediction models have been developed to diagnose unilateral PA and therefore bypass AVS. However, their generalizability remains unknown. In this retrospective study, we aimed to externally validate the performance of prediction models for unilateral PA in a large population of PA patients at a Canadian referral center who underwent AVS during 2006–2018. The presence of unilateral disease was indicated by a lateralization index of &amp;gt;3 on AVS. We identified 6 clinical prediction models from the literature. The discrimination and calibration of each model were systematically evaluated. For the original models, the derivation cohorts were based out of Japan, France, Italy, and England, with mean age between 46–54 years and 43–56% being male. The derivation cohorts were generally small, with 4 of the 6 studies reporting less than 50 people with unilateral PA. Common variables reported to be predictive of unilateral PA included male sex, hypokalemia, elevated aldosterone-renin ratio, and the presence of a unilateral adrenal nodule on imaging. The validation cohort included 342 PA patients who underwent successful AVS (average age, 52.1 years; 58.8% male). Among them, 186 (54.4%) demonstrated unilateral disease, and the remaining 156 (45.6%) were considered to have bilateral disease. The baseline characteristics of the validation cohort were broadly similar to those of the derivation cohorts, except for potential differences in ethnicity. When applying the models to the validation cohort, subjects were excluded if any candidate variables were missing. All 6 models demonstrated poor discrimination in the validation set (C-statistics; range, 0.59–0.72), representing a marked decrease compared to the derivation sets where they were reported (range, 0.80–0.87). Assessment of calibration by comparing observed and predicted probabilities of the unilateral subtype revealed significant miscalibration. Calibration-in-the-large for every model was &amp;gt;0 (range, 0.36–2.23), signifying systematic underprediction of unilateral PA. Calibration slopes were all &amp;lt;1 (range, 0.35–0.85), indicating poor performance at the extremes of risk. These results suggest that the original models were optimistic due to overfitting in the derivation cohorts and therefore lack generalizability. This is primarily because these models were developed in small data sets. In conclusion, clinical assessment with prediction models for unilateral PA cannot be readily used to bypass AVS in the general PA population.

Primary aldosteronism subtyping in the setting of partially successful adrenal vein sampling.

Background and aims:Frequent failure of adrenal vein (AV) cannulation is a major obstacle to the universal use of adrenal vein sampling (AVS) for subtyping primary aldosteronism (PA). This study aimed to confirm and modify the value of a previously reported AVS parameter for PA subtyping in the case of cannulation failure on one side.Methods:Successfully catheterized AVS studies in 157 patients (121 patients as a derivation cohort and 36 patients as a validation cohort) from two tertiary hospitals were retrospectively reviewed. The AV/inferior vena cava (IVC) index was defined by dividing the aldosterone/cortisol ratio (ACR) of AV by the ACR of the IVC. Cutoff values for lateralized PA were obtained from two methods: scatterplots and the values corresponding to Youden’s index in receiver operating characteristic (ROC) curves, on the assumption of catheterization failure on one side.Results:Due to multiple samplings in a single AVS procedure, 252 left AV/IVC ratios (LIRs) and 272 right AV/IVC ratios (RIRs) were calculated. Scatterplot cutoffs of LIR >5.4 or <0.5 predicted unilateral PA with a sensitivity of 42.1% and a specificity of 98.6%. Scatterplot cutoffs of RIR <0.5 or >7.0 showed a sensitivity of 55.1% and a specificity of 98.6%. ROC curve cutoffs of LIR ⩽0.8 or >3.1 predicted unilateral PA with a sensitivity of 82.5% and a specificity of 69.6%. ROC curve cutoffs of RIR ⩽0.8 or >3.9 resulted in 87.4% sensitivity and 80.7% specificity.Conclusion:In the case of unilateral AVS failure, the AV/IVC index may help in diagnosing PA subtype.

Significance of aldosterone gradient within left adrenal vein in diagnosing unilateral subtype of primary aldosteronism.

The success rate of cannulation of the right adrenal vein is limited. The aldosterone gradient within the same adrenal vein branch is specific for aldosterone-producing adenoma. This study was performed to investigate whether the absolute aldosterone gradient within the left adrenal vein (left-AV absolute aldosterone gradient) indicates unilateral excess aldosterone. A retrospective cross-sectional study in a single referral centre. In total, 123 consecutive patients with primary aldosteronism who had successful adrenal vein sampling (AVS) data were examined. The left-AV absolute aldosterone gradient was considered significant when a gradient of >4:1 in the aldosterone-to-cortisol ratio between the common trunk vein and central vein was found. The prevalence of the unilateral subtype in patients with a significant left-AV absolute aldosterone gradient. The prevalence of the unilateral subtype was higher in patients with than without a significant left-AV absolute aldosterone gradient (88.2% [15/17] vs 21.7% [23/106], P<.001). Of 60 patients with spontaneous hypokalemia, left unilateral disease on computed tomography, or both, a significant left-AV absolute aldosterone gradient was present only in patients with the unilateral subtype on AVS (42.9% [15/35]), but not in those with the bilateral subtype (0.0% [0/25]). These data were validated in an external cohort. The presence of a significant left-AV absolute aldosterone gradient can be used to diagnose the left unilateral subtype of primary aldosteronism on AVS in patients with spontaneous hypokalemia, left unilateral disease on computed tomography or both.

Subtyping of primary aldosteronism in patients with partially successful adrenal vein sampling

Subtyping of primary aldosteronism in patients with partially successful adrenal vein sampling

OR34-01 11C Metomidate PET-CT Identifies More Unilateral Primary Aldosteronism Than Adrenal Vein Sampling

Introduction. Adrenal vein sampling (AVS) is the current reference test to identify unilateral, surgically-curable primary aldosteronism (PA). However, AVS is invasive and technically difficult. Even in AVS-proven unilateral PA, up to 6% of patients with fail to have biochemical cure after surgery using the PASO criteria. 11C-Metomidate PET-CT offers a non-invasive alternative. We compared the accuracy of both PET-CT and AVS using post-surgery cure (PASO criteria) as the reference. Methods. This multi-centre prospective trial recruited 25 patients with confirmed PA, and all underwent CT, AVS, and PET-CT tests. Sequential AVS under ACTH-stimulation was done by an experienced interventionalist, and cortisol gradient of >5 was taken to be successful cannulation. Lateralization ratio >4 was consistent with unilateral PA. All results were reviewed at a multidisciplinary meeting to decide on the diagnosis (unilateral or bilateral PA) and management (secondary outcome). Primary outcome was biochemical cure using PASO criteria at 6 months post-surgery (ClinicalTrials.gov: NCTxxxxxxxx). Results. Recruitment for the study has been complete with 25 patients, 49.2 ± 9.5 yr, 14 females (56.0%). All 25 patients had successful AVS. 22 of 25 patients (88.0%) had unilateral PA, and 3 patients (12.0%) had bilateral PA. PET-CT identified unilateral PA in 18 of 22 patients (sensitivity 81.8%), while AVS identified unilateral PA in 15 of 22 patients (sensitivity 68.2%). In one patient, repeat AVS done simultaneously without ACTH-stimulation aided to identify unilateral PA, when initial AVS failed to do so. Other cases where AVS failed to identify unilateral PA were due to venous anomalies, and limitation of the lateralization cut-off of 4. 18 of 22 patients have undergone surgery, with 3 patients awaiting surgery, and 1 opting for medical treatment. Post-surgery, all patients had complete normalization of aldosterone-renin ratio, and hypokalemia (if present). 2 patients had bilateral PA on both PET-CT and AVS. 1 patient had discordant AVS and PET-CT results, with AVS lateralizing to right, and PET-CT to left. This patient was classified as bilateral PA and treated medically. Conclusion. This is the first study to demonstrate that 11C-Metomidate PET-CT may identify cases of unilateral PA not detected with AVS, using the stringent PASO criteria for post-operative biochemical cure.

SAT-548 Significance of Adrenal Vein Aldosterone Gradient in the Diagnosis of Unilateral Subtype of Primary Aldosteronism

Context: Adrenal vein sampling (AVS) is the standard method for subtype diagnosis in primary aldosteronism (PA), while success rate of its procedures, especially in right adrenal vein (AV), has limited. However, unilateral subtype of PA can be completely cured by surgical treatment and hence diagnostic approach for PA should be established especially when patients with apparent adrenal disease on computed tomography (CT) lack complete AVS result. In recent years, segmental AVS demonstrates that apparent aldosterone gradient in each adrenal vein branch is specific finding in aldosterone producing adenoma. Since we have reported that plasma aldosterone concentrations different in the proximal and distal regions of the left AV in some of the patients with PA, we hypothesized that solo finding of adrenal aldosterone gradient in the left AV (left AV gradient) should be the clue for unilateral subtype of PA. Objective: The aim was to investigate whether left AV gradient indicate the left unilateral subtype of PA. Design and Setting This study was a part of the Kyushu Adrenal Network Database for Advanced medicine (Q-AND-A) study, a cross-sectional and retrospective study in a single referral center. Participants and AVS procedure: Of 194 PA patients who underwent AVS with cosyntropin stimulation between January 2007 and April 2019, 111 patients had available and successful AVS data. Blood samples in left adrenal veins were obtained from following two positions; the common trunk and the central adrenal vein. We calculated left AV gradient by the ratio of aldosterone-to-cortisol ratio on the higher position in left AV to that on the lower position. We determined the presence of left AV gradient if it was greater than four. Main outcome measures: Prevalence of unilateral subtype in patients with left AV gradient who had unilateral disease on CT. Results: Of 111 patients with complete AVS data, 43 who had left unilateral disease on CT were analyzed in present study. Twenty-nine patients were diagnosed as left unilateral subtype on AVS and 14 were bilateral subtype. Aldosterone gradient was observed only in patients with unilateral subtype (41% [12/29]), not in patients with bilateral subtype (0% [0/14]). Of 29 patients with unilateral subtype on AVS, clinical parameters, including plasma aldosterone concentrations, plasma renin activity, and serum potassium levels, were not different in those with and without left AV gradient. The receiver operative curve analysis for the diagnosis of unilateral subtype on AVS showed that the optimal cutoff value of left AV gradient was 3.3 with a sensitivity of 45% and specificity of 100%. Conclusion: The presence of left AV gradient is the reliable finding for the diagnosis of left unilateral subtype in patients with PA who have unilateral disease on CT. However, further study in a larger number of cases is required to validate this finding.

The aldosterone index could be used to diagnose the dominant gland in primary aldosteronism — a retrospective study

Failed cannulation in the right adrenal vein, which makes the sampling results in the contralateral vein and inferior vena cava (IVC) nonsense, is the main obstacle of using adrenal vein sampling (AVS) in the lateralisation diagnosis in primary aldosteronism (PA). We performed a retrospective study to evaluate the specificity and sensitivity of using the aldosterone index (AI) in PA lateralisation diagnosis. We enrolled 116 patients who were diagnosed with PA and then underwent AVS in the West China Hospital of Sichuan University from April 2015 to April 2017. The AI, calculated by dividing the aldosterone concentration of the failed side by the aldosterone concentration of IVC, was used for lateralisation diagnosis if the cannulation was judged to be failed by traditional method. Patients with dominant adrenal gland based on successful AVS were included in subgroup 2 (n = 75), while the patients diagnosed with a dominant gland using AI method were enrolled in subgroup 1 (n = 41). No significant difference of clinical and biochemical findings between the two groups was detected (p value after operation > 0.05). ROC analysis was performed to test the specificity and sensitivity based on the AI in subgroup 2. The AUC for dominant gland detection was 0.76, which resulted in 91.3% sensitivity and 67.53% specificity. The positive and negative likelihood ratios were 2.81. Our data suggested that the modified strategy using AI to diagnose the dominant gland in PA is an efficient method when cannulation has failed in the right side.

Partially successful adrenal vein sampling can in some cases reveal the etiology of primary aldosteronism

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

SAT-075 Introduction of a Single Radiologist Improves the Performance of Adrenal Vein Sampling for Primary Aldosteronism, but Does Not Ameliorate Suboptimal Selection of Patients for Surgery

Context: Adrenal vein sampling (AVS) should be performed in most patients with primary aldosteronism (PA) who want to pursue surgical cure. Objective: We aimed to compare the success rate of AVS at our center after the introduction of a single dedicated radiologist in 2012 to the period before that. We tried also to find out the percentage of patients with proven unilateral PA who ultimately had surgery. Patients and methods: A retrospective diagnostic cross-sectional study conducted at Slovenian national referral center included all patients with PA who underwent AVS after its introduction in 2004 until the end of 2017. AVS was performed sequentially during continuous Synacthen stimulation. When the selectivity index, calculated as the ratio of concentrations of cortisol from an adrenal vein and the infra-adrenal inferior vena cava, was at least 5, AVS was considered successful. Lateralization index, defined as the ratio of the higher over the lower cortisol-corrected aldosterone ratio, of more than 4 indicated unilateral aldosterone excess. The data were analyzed using descriptive statistics, t-test, exact Mann-Whitney test and Fisher's exact test for group comparison, and Cohen's kappa for assessing agreement. The study was approved by the National Medical Ethics Committee. Results: Data from 214 patients were examined (152 men and 62 women; age 32-73, median 57 years; BMI 18-48, median 30 kg/m2). The average number of AVS procedures performed per year increased significantly from 7 in the 2004-2011 period to 30 in the 2012-2017 period (p<0.001). AVS was successful in 85% of the patients; AVS had to be repeated in 11% of the cases; 89% of all AVS procedures were successful. The proportion of patients with successful AVS (91% vs. 66%, p<0.001) and of successful AVS procedures (80% vs. 61%, p=0.007) was significantly higher in the recent period. Adrenal hemorrhage due to vein rupture occurred during two procedures (0.83%), both resolved conservatively. Among the patients with successful AVS, 41% had unilateral disease; among them, only 83% underwent surgery. Main reason for not having surgery was patient’s reluctance (n=8). One patient was diagnosed with liver cirrhosis and was rejected by the surgeon, two patients were lost to follow-up and three patients were still on the waiting list. The proportion of patients with unilateral disease undergoing surgery did not differ significantly between the periods (89% vs. 81%, p=0.718). Conclusions: The introduction of a single, dedicated radiologist in 2012 expanded and improved the AVS performance at our center. A substantial number of patients with proven unilateral PA did not proceed to surgery, pointing to suboptimal selection of candidates for AVS.

Partial Adrenalectomy - Arguments for the Minimally Invasive Surgical Approach.

Background: Partial adrenalectomy has been widely performed in the last decades in order to diminish the number of patients who would become lifetime dependent of hormonal replacement. Method: between 2016 and 2018 seven patients were submitted to minimally invasive partial adrenalectomy in Ponderas Academic Hospital. Results: the median age at the time of surgery was 56 years (range 42-67 years) while the indications for partial adrenalectomy (PA) were represented by Conn's syndrome in four cases, bilateral pheochromocytoma in one cases and nonfunctional adrenal tumors in two cases. Preoperatively successful adrenal vein sampling was performed in one case. The indocyanine green test (ICG) as well as intraoperative ultrasound were used each in three cases. The transperitoneal approach was used for PA in all patients, laparoscopic in five and robotic assisted in two patients. No conversion to open surgery or to total suprarenalectomy was encountered. Conclusions: minimally invasive surgery seems to be a safe and effective method to perform partial adrenalectomy. Moreover, development of novel technologies such as adrenal vein sampling, indocyanine green test or intraoperative ultrasound seem to increase the feasibility of the method as well as the number of cases who could benefit from the type of approach. Use of new technology?

A18104 The location spectrum of the right adrenal vein orifices in patients with primary aldosetronism

Objectives: To determine the distribution of the right adrenal vein orifices in patients with primary aldosteronism who underwent successful right adrenal vein sampling (AVS). Methods: 575 patients with confirmed primary aldosteronism who underwent successful AVS in the Hypertension Center of People's Hospital of Xinjiang, China between January 2006 and October 2013 were consecutively enrolled. A SIM-ADS V4.2 medical imaging workstation was used to determine the location of the right adrenal vein orifices. The distribution of the right adrenal vein orifices were analyzed according to the markers in the spine. Results: 1) the orifice of the right adrenal vein is located ranging from the middle edge of Th10 to the middle edge of Th12 in 457 patients (79.5%). Only 3.5% orifices were found between the upper edges of L1 to the middle edge of L1. 2) Distributions of the right adrenal vein orifices varied significantly in different gender, height, weight, body mass index and abdominal circumference, but the age did not show significantly different in 6 groups divided by markers in the spine. Conclusion: The middle edge of Th10 to the middle edge of Th12 should be main target area for successful right adrenal vein catheterization when performing AVS.