Usefulness and accuracy of segmental adrenal venous sampling on localisation and functional diagnosis of various adrenal lesions in primary aldosteronism

Utility of right adrenal signature veins in venous sampling for primary aldosteronism

BACKGROUND

This study aimed to identify the appropriate signature veins for the right adrenal gland using a 3D model fused with adrenal venography images and to verify their accuracy through the selectivity index (SI) >2.

METHODS

We analyzed the right adrenal venography images of 41 patients who underwent adrenal venous sampling (AVS). These images were merged with a 3D structure of the adrenal gland to identify the signature veins of the right adrenal gland. We then used the signature veins observed during adrenal venography to determine the optimal position of the catheter tip during AVS for 53 other patients. Finally, we verified the accuracy of this method according to the SI.

RESULTS

We successfully fused the 3D models of 41 cases with adrenal venography images. We identified the trunk branch type as the major venous morphology in the right anterior oblique at degrees of 30 (38 cases, 92.7%). In addition, the central vein, brush vein, uvula vein, and capsular vein were identified as signature veins for the right AVS. The accuracy of AVS was 100% in the other 53 patients, as verified by an SI >2.

CONCLUSIONS

Our study identified the right adrenal signature veins, including the previously overlooked uvula vein, which can be used to determine the position of the catheter tip and improve the success rate of AVS.

Differences between left adrenal vein sampling sites revealed with segmental sampling in primary aldosteronism

OBJECTIVES

To clarify the differences between two left sampling sites (left adrenal central vein [LCV] and common trunk [CMT], conjunction with LCV and inferior phrenic vein) and their impact on adrenal venous sampling (AVS) in primary aldosteronism by analyzing the results of segmental AVS (sAVS).

METHODS

We retrospectively analyzed a final cohort of 432 patients who underwent cosyntropin-stimulated sAVS from 2017 to 2020. Hormone levels in the LCV and the CMT were compared. Subtype diagnosis was based on the lateralization index with LCV and CMT sampling (a cutoff value of 4) and sAVS after excluding patients with a selectivity index (SI) <3.

RESULTS

Compared with the LCV, CMT sampling showed significantly lower aldosterone and cortisol levels and a higher proportion of cases with an SI of <3 (2.8% vs 0.5%, p = 0.025) and <5 (6.9% vs 0.5%, p < 0.001), while the aldosterone-to-cortisol ratio and the lateralization index were not significantly different. Subtyping of both sites was concordant in 94.7% (393/415) and discordant in the remainder, which included left and right aldosterone-producing adenoma and idiopathic hyperaldosteronism cases referring to the sAVS. There was no significant difference between the concordance rate of the two sampling sites based on the sAVS diagnosis.

CONCLUSIONS

LCV sampling meets the SI criteria for successful AVS more frequently compared with CMT sampling, but neither was better than the other in terms of diagnosis under conditions of meeting the criteria.

ADVANCES IN KNOWLEDGE

LCV sampling would decrease the number of cases judged as AVS failure.

Role of Adrenal Vein Sampling in Guiding Surgical Decision in Primary Aldosteronism

Adrenal vein sampling (AVS) is recommended for subtyping primary aldosteronism (PA) to identify lateralized or bilateral sources of aldosterone excess, allowing for better decision-making in regard to medical or surgical management on a case-by-case basis. To date, no consensus exists on protocols to be used during AVS, especially concerning sampling techniques, the timing of sampling, and whether or not to use adrenocorticotropic hormone (ACTH) stimulation. Interpretation criteria for selectivity, lateralization, and contralateral suppression vary from one expert center to another, with some favoring strict cut-offs to others being more permissive. Clinical and biochemical post-operative outcomes can also be influenced by AVS criteria utilized to indicate surgical therapy.In this review, we reanalyze studies on AVS highlighting the recent pathological findings of frequent micronodular hyperplasia adjacent to a dominant aldosteronoma (APA) overlapping with bilateral idiopathic hyperaldosteronism (IHA) etiologies, as opposed to the less frequent unilateral single aldosteronoma. The variable expression of melanocortin type 2 receptors in the nodules and hyperplasia may explain the frequent discordance in lateralization ratios between unstimulated and ACTH- stimulated samples. We conclude that aldosterone values collected during simultaneous bilateral sampling, both at baseline and post-ACTH stimulation, are required to adequately evaluate selectivity, lateralization, and contralateral suppression during AVS, to better identify all patients with PA that can benefit from a surgical indication. Recommended cut-offs for each ratio are also presented.

Can expiratory or inspiratory contrast-enhanced computed tomography be more efficient for fast-track cannulation of the right adrenal vein in adrenal venous sampling?

PURPOSE

This study compares the usefulness of expiratory arterial phase (EAP)-contrast-enhanced computed tomography (CT) (CECT) with that of inspiratory arterial phase (IAP)-CECT in adrenal venous sampling (AVS).

METHODS

Sixty-four patients who underwent AVS and CECT at the authors' hospital between April 2013 and June 2019 were included in this study. The patients were classified into the following two groups: EAP (32 patients) and IAP (32 patients) groups. The single arterial phase images were obtained at 40 seconds in the IAP group. The double arterial phase images were obtained at 40 seconds in the early arterial phase and 55 seconds in the late arterial phase in the EAP group. The authors then compared the right adrenal vein (RAV) visualization rate on the CECT, the difference between the CECT images and adrenal venograms in the localization of the RAV orifice, the cannulation time to the RAV, and the volume of contrast agent administered intraoperatively between the two groups.

RESULTS

The rates of the RAV visualization in the EAP group were 84.4% in the early arterial phase, 93.8% in the late arterial phase, and 100% in the combined early and late arterial phases. The rate of the RAV visualization in the IAP group was 96.9%. There was no significant difference between the two groups in terms of the rate of the RAV visualization. However, there was a small difference in the location of the RAV orifice between the CECT images and adrenal venograms in the EAP group as compared with the IAP group (P < 0.001). The median time to the RAV catheterization was significantly shorter in the EAP group (27.5 minutes) than in the IAP group (35.5 minutes; P = 0.035). The rates of the RAV visualization in the EAP group were not significant between the early arterial phase, late arterial phase, and combined early and late arterial phases (P = 0.066). However, the mean volume CT dose index in the combined early and late arterial phases was significantly higher than in the early and late arterial phases (P < 0.001).

CONCLUSION

The EAP-CECT is more useful for increasing the speed of the RAV cannulation due to the small difference in the localization of the RAV orifice compared to IAP-CECT. However, since EAP-CECT has double contrast arterial phases and increased radiation exposure compared to IAP-CECT, only the late arterial phase may be acceptable to reduce radiation exposure.

Node-by-node diagnosis for multiple ipsilateral nodules by segmental adrenal venous sampling in primary aldosteronism

OBJECTIVES

In patients with primary aldosteronism (PA), multiple adrenocortical nodules may be present on the surgical side. The aim of this study was to clarify the pathological diagnosis and the node-by-node diagnostic capability of segmental adrenal venous sampling (sAVS).

DESIGN

Retrospective study.

PATIENTS

A total of 162 patients who underwent adrenalectomy following sAVS were studied.

MEASUREMENTS

Multiple nodules on the surgical side were extracted while referring to contrast-enhanced computed tomography images. We also performed a detailed histopathological analysis of the resected specimens from patients undergoing sAVS, which included immunohistochemistry for CYP11B2.

RESULTS

In 11 (6.8%) patients, two to three nodules were detected on the surgical side. All patients were diagnosed by sAVS with at least one aldosterone-producing adenoma (APA) for localized aldosterone elevation in tributaries. Seven patients showed a lateralization index value of ≥4 after ACTH stimulation. Histopathologically and clinically, two patients had two or three CYP11B2-positive APAs, and the other nine patients both APAs and non-APAs. The positive predictive value of the most suspected APA, that is, the drainer that showed the highest aldosterone level by sAVS, was 11/11 (100%, 95% confidence interval [CI]: 71.5%-100%), while that for the second and third suspected APA was 3/7 (42.9%, 95% CI: 9.9%-81.6%), and they were significantly different (p = .01). Further, the positive predictive value of non-APA was 4/4 (100%, 95% CI: 39.8%-100%).

CONCLUSIONS

The sAVS could correctly diagnose the aldosterone production in multiple ipsilateral adrenal nodules.

The Entity of Connshing Syndrome: Primary Aldosteronism with Autonomous Cortisol Secretion

Connshing syndrome (CoSh) (adrenal-related synchronous aldosterone (A) and cortisol (C) excess) represents a distinct entity among PA (primary hyperaldosteronisms) named by W. Arlt et al. in 2017, but the condition has been studied for more than 4 decades. Within the last few years, this is one of the most dynamic topics in hormonally active adrenal lesions due to massive advances in steroids metabolomics, molecular genetics from CYP11B1/B2 immunostaining to genes constellations, as well as newly designated pathological categories according to the 2022 WHO classification. In gross, PA causes 4-10% of all high blood pressure (HBP) cases, and 20% of resistant HBP; subclinical Cushing syndrome (SCS) is identified in one-third of adrenal incidentalomas (AI), while CoSh accounts for 20-30% to 77% of PA subjects, depending on the tests used to confirm autonomous C secretion (ACS). The clinical picture overlaps with PA, hypercortisolemia being mild. ACS is suspected in PA if a more severe glucose and cardiovascular profile is identified, or there are larger tumours, ACS being an independent factor risk for kidney damage, and probably also for depression/anxiety and osteoporotic fractures. It seems that one-third of the PA-ACS group harbours mutations of C-related lines like PRKACA and GNAS. A novel approach means we should perform CYP11B2/CYP11B1 immunostaining; sometimes negative aldosteronoma for CYP11B1 is surrounded by micronodules or cell clusters with positive CYP11B1 to sustain the C excess. Pitfalls of hormonal assessments in CoSh include the index of suspicion (check for ACS in PA patients) and the interpretation of A/C ratio during adrenal venous sample. Laparoscopic adrenalectomy is the treatment of choice. Post-operative clinical remission rate is lower in CoSh than PA. The risk of clinically manifested adrenal insufficiency is low, but a synthetic ACTH stimulating testing might help to avoid unnecessary exposure to glucocorticoids therapy. Finally, postponing the choice of surgery may impair the outcome, having noted that long-term therapy with mineralocorticoids receptors antagonists might not act against excessive amounts of C. Awareness of CoSh improves management and overall prognosis.