Comparison of the Central Adrenal Vein and the Common Trunk of the Left Adrenal Vein for Adrenal Venous Sampling

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.

Benefits of adrenal venous sampling with preoperative four-dimensional CT imaging

BACKGROUND

The effects of adrenal venous sampling (AVS) may be limited by the anatomical variants of adrenal veins.

PURPOSE

To investigate the benefits of AVS for patients who underwent four-dimensional computed tomography (4D CT) before AVS.

MATERIAL AND METHODS

We reviewed the images of contrast-enhanced four phase three-dimensional (3D) and 4D CT in patients who received AVS between February 2010 and February 2021. A total of 112 patients (59 women; mean age = 55.3  ± 11.8 years) were enrolled. Of the entire population, 49.1% (55/112) underwent 4D CT, whereas 50.9% (57/112) underwent 3D CT. The anatomical features of adrenal veins and procedural data were obtained. Simple linear regression analyses were performed to determine the relationship between imaging protocols and AVS.

RESULTS

On comparison of the two groups, the 4D cohort had a higher success rate (98.2% vs. 78.9%; P = 0.001), shorter procedure and fluoroscopy time (73.6 ± 37.3 min vs. 110.5 ± 47.9 min; P < 0.001 and 28.7 ± 31.2 min vs. 97.4 ± 251.7 min; P = 0.047, respectively), lower radiation exposure (243.5 ± 315.5 mGycm² vs. 613.4 ± 674.6 mGycm²; P < 0.001) and less contrast volume (46.2 ± 42.7 ml vs. 68.3 ± 47.4 ml vs; P = 0.014). In simple linear regression analysis, positive and negative identification of right adrenal vein before AVS significantly influenced the success rate (unstandardized coefficients [UC] = 0.304, standardized coefficients [SC] = 0.304; P = 0.001) and operation duration (UC = -46.124, SC = -0.318; P = 0.001).

CONCLUSION

Pre-procedural 4D CT may facilitate successful AVS. Compared with four-phase 3D CT, this protocol is better to shorten the operation and fluoroscopy time, and to reduce the radiation dose and contrast consumption.

Adrenal Vein Sampling in Primary Aldosteronism: A Pictorial Essay for Optimal Left-Side Sampling

Primary aldosteronism (PA) is a curable cause of hypertension. Recent studies have revealed that the actual prevalence of PA is higher than previously recognized. Adrenal vein sampling (AVS) is an essential diagnostic procedure for revealing the cause of PA and determining the treatment plan. The success of AVS is confirmed by comparing cortisol levels between the samples from each adrenal vein and peripheral vein. The failure rate of the procedure is reported to be high in the right adrenal vein, which is directly connected to the inferior vena cava, while that in the left adrenal vein is relatively low; however, this has rarely been reported. In this review, we introduce and analyze cases of failure in left adrenal vein sampling.

Anatomical Variations of the Left Adrenal Vein Encountered During Venous Sampling

PURPOSE

To identify anatomical variations in the left adrenal vein (LAV) and to evaluate the role of preprocedural contrast-enhanced computed tomography (CT) planning.

METHODS

The length of the left adrenal central vein (LACV), the vessel that receives blood from all tributaries of the left adrenal gland, was measured using venograms of patients who had undergone adrenal venous sampling (AVS) for the diagnosis of primary aldosteronism between October 2017 and December 2019. The anatomical variants of the LAV were described and classified. Contrast-enhanced CT was used to evaluate the detection rate of the following: (a) confluence of the left inferior phrenic vein and the LAV and (b) the last tributary flowing into the LAV.

RESULTS

In total, 311 patients (143 men, 168 women; mean age: 49.3 years ± 11.0) were enrolled. Of them, 9 (2.9%) patients had anatomical variants lacking a LACV. In patients with a LACV (n = 302), the venographic LACV length was 9.0 mm ± 3.9 (<1 mm in 9 patients). The detection rate of the confluence of the left inferior phrenic vein and LAV, as determined using contrast-enhanced CT, was high (96.2%), whereas that of the last tributary flowing into the LAV was low (0.8%). In 4 of 18 patients with short or absent LACV, the variant was visualized using contrast-enhanced CT.

CONCLUSIONS

In some patients, the LACV is absent or short, which is an anatomical variation. Understanding venographic anatomical variations can help avoid misleading results resulting from a suboptimal sampling site in AVS. For some subtypes, contrast-enhanced CT may also help in planning the AVS procedure.

A Rare Independent Left Inferior Phrenic Vein Sampling in a Left Adrenal Aldosterone-Producing Adenoma

This report presents a case of left adrenal aldosterone-producing adenoma (APA) diagnosed by segmental adrenal venous sampling in a patient with primary aldosteronism and a rare venous anomaly in which the left inferior phrenic vein (LIPV) and adrenal central vein entered the left renal vein separately. The outflow of tumor blood into the LIPV and the specimen from the LIPV that showed much higher aldosterone level than that from the adrenal central vein and tributaries were useful for proving the aldosterone hypersecretion from the APA. Sampling from the LIPV could be of diagnostic value for left APA.

Adrenal vein sampling: technique and protocol, a systematic review

Primary aldosteronism is the leading cause of secondary hypertension worldwide. Its deleterious effects outstrip those due to blood pressure elevation alone. An essential part of the work-up of a patient with primary aldosteronism is determining if aldosterone production is unilateral or bilateral. With the former, surgery offers a potential cure and better overall outcomes. Adrenal vein sampling is considered the most reliable method to determine whether production is unilateral or bilateral. Sampling may be non-diagnostic when the vein cannot be properly cannulated. But with proper knowledge and experience as well as the utilization of certain techniques, procedure success can be high. Multiple protocols exist; their rationale and drawbacks are reviewed here. This article will give the reader an overview of techniques for improving procedural success as well as background, rationale and evidence to guide one in choosing the appropriate procedural and interpretation protocol.

Utility of microcatheter in adrenal venous sampling for primary aldosteronism

OBJECTIVE

To evaluate the utility of microcatheter in adrenal venous sampling (AVS) for assessing aldosterone hypersecretion and the laterality in patients with primary aldosteronism.

METHODS

This retrospective study was approved by the institutional review board of Gifu University Hospital, and written informed consent was waived. A total of 37 consecutive patients with primary aldosteronism underwent AVS by inserting a microcatheter into the right adrenal central vein (RCV), left adrenal central vein (LCV), and left adrenal common trunk (CT) followed by AVS with 5-French (5-Fr) catheter. The diagnosis of aldosterone hypersecretion was confirmed if the plasma aldosterone level after the administration of cosyntropin injection was ≥14,000 pg/ml. The laterality of aldosterone hypersecretion was determined based on the lateralized and contralateral ratios. Aldosterone hypersecretion and the laterality were diagnosed and compared based on the results obtained using 5-Fr catheter and microcatheter.

RESULTS

Plasma aldosterone levels were significantly higher in the RCV, LCV, and CT selected using microcatheter than in the right and left adrenal veins (LAVs) selected using 5-Fr catheter (p < 0.0001-0.029). More aldosterone hypersecretion from the left adrenal gland was observed in the LCV (n = 28) and CT (n = 25) selected using microcatheter compared to the LAV selected using 5-Fr catheter (n = 6) (p < 0.0001). Diagnostic changes in the laterality from unilateral to bilateral were noted in 3 (8%) patients using microcatheter.

CONCLUSION

Microcatheter can effectively assess aldosterone hypersecretion and the laterality, especially in the LAV.

ADVANCES IN KNOWLEDGE

Especially for the left adrenal venous sampling, the tip of microcatheter could certainly reach the left adrenal vein orifice compared with 5-Fr catheter, therefore correct diagnosis is made and this leads to appropriate treatment.

Niche point-of-care endocrine testing - Reviews of intraoperative parathyroid hormone and cortisol monitoring

Point-of-care (POC) testing, which provides quick test results in near-patient settings with easy-to-use devices, has grown continually in recent decades. Among near-patient and on-site tests, rapid intraoperative and intra-procedural assays are used to quickly deliver critical information and thereby improve patient outcomes. Rapid intraoperative parathyroid hormone (ioPTH) monitoring measures postoperative reduction of parathyroid hormone (PTH) to predict surgical outcome in patients with primary hyperparathyroidism, and therefore contributes to the change of parathyroidectomy to a minimally invasive procedure. In this review, recent progress in applying ioPTH monitoring to patients with secondary and tertiary hyperparathyroidism and other testing areas is discussed. In-suite cortisol monitoring facilitates the use of adrenal vein sampling (AVS) for the differential diagnosis of primary aldosteronism and adrenocorticotropic hormone (ACTH)-independent Cushing syndrome. In clinical and psychological research settings, POC testing is also useful for rapidly assessing cortisol in plasma and saliva samples as a biomarker of stress. Careful resource utilization and coordination among stakeholders help to determine the best approach for implementing cost-effective POC testing. Technical advances in integrating appropriate biosensors with microfluidics-based devices hold promise for future real-time POC cortisol monitoring.

Optimization of left adrenal vein sampling in primary aldosteronism: Coping with asymmetrical cortisol secretion

We evaluated the influence of catheter sampling position and size on left adrenal venous sampling (AVS) in patients with primary aldosteronism (PA) and analyzed their relationship to cortisol secretion. This retrospective study included 111 patients with a diagnosis of primary aldosteronism who underwent tetracosactide-stimulated AVS. Left AVS was obtained from two catheter positions - the central adrenal vein (CAV) and the common trunk. For common trunk sampling, 5-French catheters were used in 51 patients, and microcatheters were used in 60 patients. Autonomous cortisol secretion was evaluated with a low-dose dexamethasone suppression test in 87 patients. The adrenal/inferior vena cava cortisol concentration ratio [selectivity index (SI)] was significantly lower in samples from the left common trunk than those of the left CAV and right adrenal veins, but this difference was reduced when a microcatheter was used for common trunk sampling. Sample dilution in the common trunk of the left adrenal vein can be decreased by limiting sampling speed with the use of a microcatheter. Meanwhile, there was no significant difference in SI between the left CAV and right adrenal veins. Laterality, determined according to aldosterone/cortisol ratio (A/C ratio) based criteria, showed good reproducibility regardless of sampling position, unlike the absolute aldosterone value based criteria. However, in 11 cases with autonomous cortisol co-secretion, the cortisol hypersecreting side tended to be underestimated when using A/C ratio based criteria. Left CAV sampling enables symmetrical sampling, and may be essential when using absolute aldosterone value based criteria in cases where symmetrical cortisol secretion is uncertain.

Optimum position of left adrenal vein sampling for subtype diagnosis in primary aldosteronism

CONTEXT

Although adrenal vein sampling (AVS) is the standard method for subtype diagnosis in primary aldosteronism (PA), protocol details including the sampling position in the adrenal vein are not standardized.

OBJECTIVE

To establish the optimum sampling position in the left adrenal vein based on postoperative outcome in PA patients.

DESIGN AND SETTING

Retrospective study in nine referral centres.

PARTICIPANTS

Of 496 consecutive PA patients who underwent AVS between 2006 and 2013, 217 with successful AVS under cosyntropin stimulation, and with concomitant data from two positions: proximal (common trunk) and distal (central vein) to the junction with the inferior phrenic vein, were included.

MAIN OUTCOME MEASURES

Discordant rate of subtype diagnosis between common trunk and central vein, and postoperative outcomes in patients with discordant results.

RESULTS

Subtype diagnosis using common trunk and central vein was discordant in 10 (4·6%) of the 217 patients (κ = 0·87, P < 0·05). Of these 10 patients, eight with left unilateral subtype and two with bilateral subtype using common trunk data showed bilateral subtype and unilateral subtype, respectively, using central vein data. Five patients with left unilateral subtype and one with bilateral subtype by common trunk data underwent unilateral adrenalectomy. All six patients were cured of PA after adrenalectomy, resulting in false-negative rates of 17% (1/6) by common trunk data, and 83% (5/6) by central vein data.

CONCLUSION

In view of its better potential diagnostic accuracy, technical ease, lower cost and lower risk of vein rupture, blood sampling from the common trunk of the left adrenal vein may be preferable as the standard method of AVS in patients with PA, although additional studies in a larger number of cases are required.

Intra-adrenal Aldosterone Secretion: Segmental Adrenal Venous Sampling for Localization

PURPOSE

To use segmental adrenal venous sampling (AVS) (S-AVS) of effluent tributaries (a version of AVS that, in addition to helping identify aldosterone hypersecretion, also enables the evaluation of intra-adrenal hormone distribution) to detect and localize intra-adrenal aldosterone secretion.

MATERIALS AND METHODS

The institutional review board approved this study, and all patients provided informed consent. S-AVS was performed in 65 patients with primary aldosteronism (34 men; mean age, 50.9 years ± 11 [standard deviation]). A microcatheter was inserted in first-degree tributary veins. Unilateral aldosterone hypersecretion at the adrenal central vein was determined according to the lateralization index after cosyntropin stimulation. Excess aldosterone secretion at the adrenal tributary vein was considered to be present when the aldosterone/cortisol ratio from this vein exceeded that from the external iliac vein; suppressed secretion was indicated by the opposite pattern. Categoric variables were expressed as numbers and percentages; continuous variables were expressed as means ± standard errors of the mean.

RESULTS

The AVS success rate, indicated by a selectivity index of 5 or greater, was 98% (64 of 65). The mean numbers of sampled tributaries on the left and right sides were 2.11 and 1.02, respectively. The following diagnoses were made on the basis of S-AVS results: unilateral aldosterone hypersecretion in 30 patients, bilateral hypersecretion without suppressed segments in 22 patients, and bilateral hypersecretion with at least one suppressed segment in 12 patients. None of the patients experienced severe complications.

CONCLUSION

S-AVS could be used to identify heterogeneous intra-adrenal aldosterone secretion. Patients who have bilateral aldosterone-producing adenomas can be treated with adrenal-sparing surgery or other minimally invasive local therapies if any suppressed segment is identified at S-AVS.