medwireNews: UK researchers have developed a technique involving molecular imaging-located, endoscopic ultrasound-guided, transgastric radiofrequency ablation (EUS-RFA) as a minimally invasive treatment for aldosterone-producing adrenal adenomas (APAs) in the left adrenal gland.
At present, treatment of unilateral APAs, which are the potentially curable cause of 5% of all cases of hypertension, requires localization via adrenal vein sampling (AVS) and removal by laparoscopic adrenalectomy.
These “invasive procedures are unattractive to patients,” with many saying they would prefer an endoscopic procedure “even if eventual efficacy proved to be less than half that of surgery,” report Morris Brown (Queen Mary University of London, UK) and co-authors in The Lancet.
To address this, they developed the EUS-RFA method and carried out the phase 1 FABULAS trial to test whether it could be safely used to visualize, enter, and ablate small APAs in the left adrenal gland via the stomach without damaging the rest of the adrenal gland or adjacent organs.
The study included 28 participants (75% men, mean age 58 years) with primary aldosteronism and a left-sided APA. They underwent functional adrenal imaging with either 11C-metomidate or para-chloro-2-[18F]fluoroethyletomidate positron emission tomography–computed tomography (PET–CT) first to diagnose and locate the APA, and later to quantify the degree of ablation.
The EUS-RFA procedure involved visualization of the left adrenal gland and then RFA using a 19G ablation catheter. Movement of the catheter under continuous EUS guidance allowed an incremental number of 5–20 s treatments as the study progressed, with treatments ranging from one to 14 burns per nodule, and a total procedure duration of around 20 minutes.
The majority (75%) of participants underwent a single EUS-RFA but a quarter of the cohort underwent a second procedure after the 3-month PET–CT scan showed less than 25% ablation of the target nodule.
The researchers report that in the 24–48 hours post-ablation, there were no cases of the prespecified major hazards, namely gastric and adrenal puncture with perforation, hemorrhage, or infarction of major organs.
Completeness of ablation was assessed at 3 months by measuring changes in the ratio for the maximum standardized uptake value for radiotracer on the left versus right adrenal gland. The team found that the median reduction was a significant 0.27.
At 6 months post-RFA, 75% of participants had complete or partial biochemical cure (≥50 reduction in plasma aldosterone), and 43% had complete or partial clinical cure (≥50% reduction in antihypertensive medication, or systolic and diastolic blood pressure [BP] reductions of 20 mmHg and 10 mmHg, respectively).
Of note, four of the 16 participants with complete biochemical success also met the criteria for complete clinical success, defined as a systolic BP below 135 mmHg and diastolic BP below 85 mmHg while off antihypertensive treatment.
Brown et al say: “EUS-RFA’s trans-gastric approach, benefiting from the short distance from stomach to the left adrenal gland, appears to overcome concerns about safety and accuracy of percutaneous ablation, which have prevented its widespread adoption into guidelines and clinical practice.”
They add that their data “have informed the design of a pivotal study [WAVE] of thermal ablation versus surgery, which will determine the full benefits of EUS-RFA.”
In an accompanying comment, Alexander Leung and Gregory Kline, both from the University of Calgary in Alberta, Canada, say that if the FABULAS findings are confirmed, EUS-RFA “might permit more people to reach definitive solutions for primary aldosteronism, including those who lack access to or have contraindications to AVS (eg, advanced kidney disease, severe uncontrolled hypertension, or the inability to stop confounding medications), those who have financial or geographical barriers to surgery, and those for whom adrenalectomy may be deemed too risky (eg, high BMI, advanced age, or complex comorbidities).”
They add: “On a population level, the biggest benefit might just be for the average person with primary aldosteronism who wants definitive treatment but is not inclined to invasive investigation or surgery.”
medwireNews is an independent medical news service provided by Springer Healthcare Ltd. © 2025 Springer Healthcare Ltd, part of the Springer Nature Group
Lancet 2025; doi:10.1016/S0140-6736(24)02755-7
Lancet 2025; doi:10.1016/S0140-6736(25)00051-0
