Adrenal artery ablation for primary aldosteronism without apparent aldosteronoma: An efficacy and safety, proof-of-principle trial

Efficacy and safety of radiofrequency ablation and laparoscopic adrenalectomy for primary aldosteronism: a meta‑analysis

OBJECTIVE

To compare the efficacy (including blood pressure, medication reduction, serum potassium, and clinical success) and safety parameters (including operative time, length of hospital stay, blood loss, hypertension crisis rate, and complication rate) of radiofrequency ablation (RFA) and laparoscopic adrenalectomy (LA) in the treatment of primary aldosteronism (PA).

METHODS

Literature search was performed on PubMed, EMBASE, The Cochrane Library (Issue 8, 2023), Web of Science, China National Knowledge Infrastructure, and Wanfang from inception to August 2023. Study selection, data extraction, and risk of bias assessment were performed by two independent reviewers. Quality assessment was conducted using the Newcastle-Ottawa scale. The Stata 12.0 software was used for statistical analyses. Pooled odds ratios (OR) with corresponding 95% confidence interval (CI) were calculated for categorical outcomes, while mean difference (MD) with corresponding 95% CI were calculated for continuous outcomes.

RESULTS

A total of 5 studies involving 204 patients (LA, n = 127; and RAF, n = 77) were included. LA had better diastolic blood pressure control than RFA (WMD = 5.19; 95% CI 0.96-9.43); however, the RFA demonstrated better shorter operative time (WMD = - 57.99; 95% CI - 116.54 to 0.57), and shorter length of hospital stay (OR - 1.6; 95% CI - 2.37 to - 0.83) compared to LA. All remaining parameters were comparable between the interventions.

CONCLUSION

While grossly comparable in efficacy as treatment options for PA, RFA may allow for shorter operative time and hospital stay, less intraoperative blood loss, and lower hospitalization costs. However, LA has better diastolic blood pressure control. Even so, we still need larger prospective studies, specifically with comparative hypertension response (short and long term) and number of post-procedural antihypertensive medication requirement.

The impact of superselective adrenal artery embolization on renal function in patients with primary aldosteronism: a prospective cohort study

Superselective adrenal artery embolization (SAAE) is an effective treatment for patients with primary aldosteronism (PA). However, the impact of SAAE on renal function in the PA population remains uncertain. We investigated the estimated glomerular filtration rate (eGFR) and age, sex, body mass index, and diabetes-specific percentiles of eGFR residuals in 182 PA patients treated with SAAE in a prospective cohort from Nanchang SAAE in treating PA registry study. Data suggest that SAAE caused a significant decrease in eGFR from 91.9 ± 26.1 to 88.7 ± 24.1 ml/min/1.73 m2 (p < 0.05) after a median follow-up of 8 months in PA patients. Patients experienced a significant decrease in eGFR from 110.6 ± 18.9 to 103.8 ± 18.2 ml/min/1.73 m2 (p < 0.001) and a very slight increase from 71.1 ± 14.8 to 71.8 ± 17.8 ml/min/1.73 m2 (p = 0.770) with baseline eGFR ≥90 and <90 ml/min/1.73 m2, respectively. Patients with high eGFR residuals (glomerular hyperfiltration) experienced a significant decrease in their eGFR levels from 123.1 ± 22.6 to 105.0 ± 18.6 ml/min/1.73 m2 (p < 0.001). In contrast, there was no significant impact of SAAE on the eGFR of patients with normal or low eGFR residuals. The very early eGFR changes (24 h after SAAE) best predicted the effect of SAAE on eGFR changes after median of eight months in PA patients. On the whole, SAAE seems to have a beneficial impact on renal function in patients with PA, the results of which vary depending on the patient's baseline eGFR and glomerular hyperfiltration status.

Treatment of primary aldosteronism: Clinical practice guidelines of the Taiwan Society of Aldosteronism

Primary aldosteronism (PA) is the most common cause of secondary hypertension and one of the few medical diseases that can be cured by surgery. Excessive aldosterone secretion is highly associated with cardiovascular complications. Many studies have shown that patients with unilateral PA treated with surgery have better survival, cardiovascular, clinical, and biochemical outcomes than those who receive medical treatment. Consequently, laparoscopic adrenalectomy is the gold standard for treating unilateral PA. Surgical methods should be individualized according to the patient's tumor size, body shape, surgical history, wound considerations, and surgeon's experience. Surgery can be performed through a transperitoneal or retroperitoneal approach, and via a single-port or multi-port laparoscopic approach. However, total or partial adrenalectomy remains controversial in treating unilateral PA. Partial excision will not completely eradicate the disease and is prone to recurrence. Mineralocorticoid receptor antagonists should be considered for patients with bilateral PA or patients who cannot undergo surgery. There are also emerging alternative interventions, including radiofrequency ablation and transarterial adrenal ablation, for which data on long-term outcomes are currently lacking. The Task Force of Taiwan Society of Aldosteronism developed these clinical practice guidelines with the aim of providing medical professionals with more updated information on the treatment of PA and improving the quality of care.

Treating Primary Aldosteronism-Induced Hypertension: Novel Approaches and Future Outlooks

Primary aldosteronism (PA) is the most common cause of secondary hypertension and is associated with increased morbidity and mortality when compared with blood pressure-matched cases of primary hypertension. Current limitations in patient care stem from delayed recognition of the condition, limited access to key diagnostic procedures, and lack of a definitive therapy option for nonsurgical candidates. However, several recent advances have the potential to address these barriers to optimal care. From a diagnostic perspective, machine-learning algorithms have shown promise in the prediction of PA subtypes, while the development of noninvasive alternatives to adrenal vein sampling (including molecular positron emission tomography imaging) has made accurate localization of functioning adrenal nodules possible. In parallel, more selective approaches to targeting the causative aldosterone-producing adrenal adenoma/nodule (APA/APN) have emerged with the advent of partial adrenalectomy or precision ablation. Additionally, the development of novel pharmacological agents may help to mitigate off-target effects of aldosterone and improve clinical efficacy and outcomes. Here, we consider how each of these innovations might change our approach to the patient with PA, to allow more tailored investigation and treatment plans, with corresponding improvement in clinical outcomes and resource utilization, for this highly prevalent disorder.

Unilateral chemical ablation of the adrenal gland lowers blood pressure and alleviates target organ damage in spontaneously hypertensive rats

Adrenal gland hormones play a critical role in the development and maintenance of hypertension. Adrenal ablation has been used to treat primary aldosteronism but not essential hypertension. The present study aimed to investigate the effectiveness and safety of unilateral adrenal gland ablation in treating spontaneously hypertensive rats (SHR). SHR and Wistar-Kyoto rats (WKY) were subjected to unilateral adrenal ablation with injection of anhydrous ethanol or a sham procedure. Blood pressure was monitored by both tail-cuff plethysmography and telemetry until 6 months after the procedure. Adrenal ablation significantly lowered systolic and diastolic blood pressure of the SHR (P < 0.05 or P < 0.01) but not WKY from 4 to 24 weeks after the procedure. Adrenal ablation substantially damaged adrenal cortex and medulla with fibrosis in SHR and WKY rats. The ablation procedure remarkably reduced the levels of renin, angiotensin II, aldosterone, cortisol, noradrenaline, and epinephrine in SHR (all P < 0.05) but not in WKY. Hypokalemia in SHR was significantly improved by adrenal ablation (P < 0.05), while the serum sodium levels were not affected by adrenal ablation in either SHR or WKY rats. Additionally, adrenal ablation improved cardiac, renal, and vascular remodeling and function measured 3 months after the procedure in SHR. In conclusion, the present study shows that ethanol ablation of adrenal gland can effectively lower blood pressure and prevent target organ damage in SHR. These findings suggest that unilateral debulking of the adrenal gland using ethanol ablation is a promising therapeutic strategy for treating hypertension.

METHODS

Spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY) were subjected to unilateral adrenal ablation with injection of ethanol or a sham procedure. Blood pressure was monitored for 24 weeks.

RESULTS

Adrenal ablation significantly lowered systolic and diastolic blood pressure of SHR but not WKY from 4 to 24 weeks after the procedure.

CONCLUSION

Unilateral debulking of the adrenal gland using ethanol ablation is a promising therapeutic strategy for treating hypertension.

Radiofrequency Ablation in Primary Aldosteronism

The radiofrequency ablation (RFA) technique has been extensively used in the treatment of primary malignancies and metastases and has been recently deployed for the treatment of unilateral primary aldosteronism (PA) as an alternative to whole unilateral adrenalectomy.Current evidence comparing RFA with unilateral adrenalectomy in the treatment of PA so far has been variable, with studies being retrospective and small-scale, but it remains a very attractive option as a potentially less invasive treatment option compared to adrenalectomy.This review article describes the procedure, and provides evidence and the possible future direction of RFA in the treatment of unilateral PA.

The outcomes of transcatheter adrenal ablation in patients with primary aldosteronism: a systematic review and meta-analysis

BACKGROUND

The use of transcatheter adrenal ablation as an alternative treatment for primary aldosteronism (PA) patients remains a subject of debate, with outcomes varying widely across existing studies. This meta-analysis aims to evaluate the results of adrenal ablation and estimate the effectiveness and safety of this therapeutic approach.

METHODS

A comprehensive search was conducted across PubMed, Embase, and Cochrane Library databases for studies published up to October 2022. Outcomes analyzed included the combined clinical success rate, biochemical success rate, and complication rate, which were assessed using a random-effects model.

RESULTS

Five studies, comprising 234 PA patients, were included in the analysis. The combined clinical success rate was 74% (95% CI: 69%-79%), and the biochemical success rate was 74% (95% CI: 53%-95%). Subgroup analysis revealed that the combined clinical success rate from Unilateral PA (72%, 95% CI: 46%-98%) was similar to the rate from Unilateral + Bilateral (73%, 95% CI: 52.0%-94.0%), while the clinical success rate of the PASO subgroup (78%, 95% CI: 66.0%-89.0%) was higher than the rate of other criteria (51%, 95% CI: 40.0%-63.0%). The combined complication rates were as follows: mild fever, 23% (95% CI: 12%-33%); back pain, 84% (95% CI: 77%-91%); and pleural effusion, 9% (95% CI: 0%-18%). All complications resolved within one week following the procedure. No late complications or ablation-related deaths were reported.

CONCLUSIONS

Transcatheter adrenal ablation for PA patients is safe and demonstrates a relatively high clinical success rate. Presently, this approach is suitable for PA patients who are unwilling to undergo surgery or receive long-term mineralocorticoid receptor antagonist (MRA) treatment.

SYSTEMATIC REVIEW REGISTRATION

INPLASY, identifier 2022110076.

Superselective adrenal arterial embolization for primary aldosteronism without lateralized aldosterone secretion: an efficacy and safety, proof-of-principle study

Superselective adrenal arterial embolization (SAAE) appears to be beneficial in primary aldosteronism (PA) patients with lateralized aldosterone secretion (unilateral PA). As confirmed by adrenal vein sampling (AVS), nearly 40% of PA patients would be PA without lateralized aldosterone secretion (bilateral PA). We aimed to investigate the efficacy and safety of SAAE on bilateral PA. We identified 171 bilateral PA patients from 503 PA patients who completed AVS. Thirty-eight bilateral PA patients received SAAE, and 31 completed a median 12-month clinical follow-up. The blood pressure and biochemical improvements of these patients were carefully analyzed. 34% of patients were identified as bilateral PA. Plasma aldosterone concentration, plasma renin activity, and aldosterone/renin ratio (ARR) were significantly improved 24-h after SAAE. SAAE was associated with 38.7% and 58.6% of complete/partial clinical and biochemical success within a median 12-month follow-up. A significant reduction in left ventricular hypertrophy was shown in patients who obtained complete biochemical success compared with partial/absent biochemical success. SAAE was associated with a more apparent nighttime blood pressure reduction than daytime blood pressure reduction in patients with complete biochemical success. No major adverse safety events related to SAAE were reported during the intraoperative, postoperative, and follow-up periods. SAAE was associated with blood pressure and biochemical improvements in part of bilateral PA and appeared safe. The biochemistry success was accompanied by improved cardiac remodeling and a more prominent decrease in nocturnal blood pressure. This study was part of a trial registered with the Chinese Clinical Trial Registry, number ChiCTR2100047689.

Catheter-based adrenal ablation: an alternative therapy for patients with aldosterone-producing adenoma

Unilateral adrenalectomy is the standard treatment for patients with aldosterone-producing adenoma (APA), but it lacks an option for patients with APA who refuse or are not suitable for surgery. In this study, we studied whether catheter-based adrenal ablation for APA is comparable to adrenalectomy. A total of 2185 hypertensive patients were screened, and 112 patients with APA were recruited and counselled on the treatment options. Fifty-two patients opted for catheter-based adrenal ablation, and 60 opted for adrenalectomy. Clinical and biochemical outcomes were assessed at 6 months after treatment. Factors associated with hypertension remission and the advantages and limitations of this approach were evaluated. According to the primary aldosteronism surgical outcome (PASO) criteria, complete and partial clinical success was achieved in 21 (40.4%) and 23 (44.2%) patients in the ablation group vs. 33 (55.0%) and 23 (38.3%) patients in the adrenalectomy group, respectively. Complete and partial biochemical success was achieved in 30 (57.7%) and 17 (32.7%) patients in the ablation group vs. 51 (85.0%) and 5 (8.3%) patients in the adrenalectomy group, respectively. The complete clinical success rate was not (P > 0.05), but the complete biochemical success rate was significantly different between the two groups (P < 0.01). Factors associated with adrenal ablation-mediated hypertension remission were hypertension duration and serum potassium level at baseline. Compared with surgery, adrenal ablation requires a shorter operating time and time to resume physical activity. Catheter-based adrenal ablation may be an alternative and feasible option for APA patients unwilling to receive surgical treatment.

Primary Aldosteronism: State-of-the-Art Review

We are witnessing a revolution in our understanding of primary aldosteronism (PA). In the past 2 decades, we have learned that PA is a highly prevalent syndrome that is largely attributable to pathogenic somatic mutations, that contributes to cardiovascular, metabolic, and kidney disease, and that when recognized, can be adequately treated with widely available mineralocorticoid receptor antagonists and/or surgical adrenalectomy. Unfortunately, PA is rarely diagnosed, or adequately treated, mainly because of a lack of awareness and education. Most clinicians still possess an outdated understanding of PA; from primary care physicians to hypertension specialists, there is an urgent need to redefine and reintroduce PA to clinicians with a modern and practical approach. In this state-of-the-art review, we provide readers with the most updated knowledge on the pathogenesis, prevalence, diagnosis, and treatment of PA. In particular, we underscore the public health importance of promptly recognizing and treating PA and provide pragmatic solutions to modify clinical practices to achieve this.

Adrenal Ablation Versus Mineralocorticoid Receptor Antagonism for the Treatment of Primary Aldosteronism: A Single-Center Prospective Cohort Study

BACKGROUND

Superselective adrenal arterial embolization (SAAE) is an alternative treatment for patients with primary aldosteronism (PA). This single-center prospective cohort study aimed to compare the efficacy of SAAE with mineralocorticoid receptor antagonists (MRA) in treating patients with PA who refused unilateral adrenalectomy.

METHODS

Of the 140 PA patients who were enrolled in the study and completed 12-month follow-up, 74 patients underwent SAAE and 66 received MRA treatment. The clinical and biochemical outcome was compared at 1, 6, and 12 months after the procedure.

RESULTS

Baseline clinical and biochemical characteristics of the patients were similar between groups. Office, home, and ambulatory blood pressure reduction at 1 month after discharge was more pronounced in the SAAE group than MRA group (all P < 0.05) while the blood pressure reduction was comparable between the 2 groups at 6 and 12 months. Patients who underwent SAAE took less antihypertensive medications than the MRA group during 12-month follow-up (P < 0.01). Both SAAE and MRA treatment improved renin suppression, aldosterone-to-renin ratio elevation, and hypokalemia at 6 and 12 months, whereas only SAAE but not MRA reduced plasma aldosterone levels. Moreover, SAAE achieved higher rates of complete clinical and biochemical success than MRA (both P < 0.01). Logistic regression found that complete clinical and biochemical success was only directly associated with diagnosis of unilateral PA in contrast to bilateral PA (P < 0.01).

CONCLUSIONS

The present study provides evidence that SAAE is a reasonable choice of treatment in patients with either unilateral or bilateral PA in terms of clinical and biochemical outcomes. This study was registered at Chictr.org.cn (ChiCTR2100045896).

Japan Endocrine Society clinical practice guideline for the diagnosis and management of primary aldosteronism 2021

Primary aldosteronism (PA) is associated with higher cardiovascular morbidity and mortality rates than essential hypertension. The Japan Endocrine Society (JES) has developed an updated guideline for PA, based on the evidence, especially from Japan. We should preferentially screen hypertensive patients with a high prevalence of PA with aldosterone to renin ratio ≥200 and plasma aldosterone concentrations (PAC) ≥60 pg/mL as a cut-off of positive results. While we should confirm excess aldosterone secretion by one positive confirmatory test, we could bypass patients with typical PA findings. Since PAC became lower due to a change in assay methods from radioimmunoassay to chemiluminescent enzyme immunoassay, borderline ranges were set for screening and confirmatory tests and provisionally designated as positive. We recommend individualized medicine for those in the borderline range for the next step. We recommend evaluating cortisol co-secretion in patients with adrenal macroadenomas. Although we recommend adrenal venous sampling for lateralization before adrenalectomy, we should carefully select patients rather than all patients, and we suggest bypassing in young patients with typical PA findings. A selectivity index ≥5 and a lateralization index >4 after adrenocorticotropic hormone stimulation defines successful catheterization and unilateral subtype diagnosis. We recommend adrenalectomy for unilateral PA and mineralocorticoid receptor antagonists for bilateral PA. Systematic as well as individualized clinical practice is always warranted. This JES guideline 2021 provides updated rational evidence and recommendations for the clinical practice of PA, leading to improved quality of the clinical practice of hypertension.

Clinical Characteristics of Target Organ Damage in Primary Aldosteronism with or without Metabolic Syndrome

The aim of this study is to investigate the prevalence of metabolic disorders in patients with primary aldosteronism (PA) and target organ damage (TOD) in different subtypes of patients with PA with or without metabolic syndrome (MS). Patients with PA were screened out from those with secondary hypertension and then subtyped via adrenal venous sampling (AVS). Baseline clinical characteristics (blood pressure, blood glucose, abdominal circumference, and lipid profile) were collected for the diagnosis of MS. Organ damage was evaluated according to cardiac and carotid ultrasound and urine microalbumin measurements. In all 261 patients with PA, 113 patients had concomitant MS and experienced more severe cardiac hypertrophy and increased intima-media thickness (IMT). The incidence of MS and diabetes mellitus (DM) had no statistic difference between the two groups, moreover, the rates of TOD were not different except microalbuminuria. However, metabolic disorders caused more remarkable TOD in PA patients with unilateral hypersecretion. It showed that cardiac hypertrophy was associated with obesity while microalbuminuria was related to plasma aldosterone concentration (PAC) in PA patients. In this retrospective study, our findings suggest that the effect of metabolic disorders on organ damage is more remarkable in patients with unilateral PA.

Therapeutic Outcomes with Surgical and Medical Management of Primary Aldosteronism

PURPOSE OF REVIEW

Primary aldosteronism (PA) is the most common cause of secondary hypertension and is significantly under-diagnosed. Delays in diagnosis and treatment can lead to cardiovascular morbidity and mortality. The goal of this study is to review the management of PA, with a focus on medical and surgical treatment outcomes.

RECENT FINDINGS

PA causes cardiovascular dysfunction in excess of degree of hypertension. Adrenalectomy demonstrates a therapeutic advantage over mineralocorticoid antagonist (MRA) therapy, after controlling for degree of hypertension and subtype of PA. Higher rates of atrial fibrillation, heart failure, stroke, and incidence of chronic kidney disease are observed in subjects treated with MRAs than in subjects treated with adrenalectomy. The therapeutic benefit of surgery may reflect definitive resolution of excess aldosterone. Complete mineralocorticoid blockade may achieve similar benefit to adrenalectomy. Adrenalectomy is the most effective treatment for unilateral PA. Biomarkers for MRA therapy might inform optimal medical therapy of bilateral adrenal hyperplasia.