Radiofrequency Ablation for Benign Aldosterone-Producing Adenoma: A Scarless Technique to an Old Disease

Bipolar Radiofrequency Ablation of the Adrenal Gland: In Vivo and Ex Vivo Experiments

Laparoscopic adrenalectomy is currently the standard treatment modality for unilateral aldosterone-producing adenoma (APA); however, a less-invasive treatment is needed for its treatment. A new bipolar ablation system that poses a lower risk of complications has been recently developed. This study aimed to evaluate the safety and performance of a novel bipolar radiofrequency ablation (RFA) system for the treatment of APAs. Ablations were performed in an ex vivo study using bovine adrenal glands [group A: n = 6, single-probe; group B: n = 6, two probes, interprobe distance (ID) = 12 mm; group C: n = 6, two probes, ID = 20 mm]. The in vivo study was conducted in groups A and B (n = 2 each) using porcine adrenal glands. For the ex vivo study, the mean vertical diameter (Dv) of the coagulative necrosis area and the mean transverse diameter (Dt) values were 11.99 mm and 10.96 mm for group A, 12.66 mm and 10.0 mm for group B, and 23.37 mm and 22.10 mm for group C, respectively. For the in vivo study, the mean Dv and Dt values were 12.23 mm and 9.03 mm for group A, and 16.38 mm and 9.52 mm for group B, respectively. No heat-induced damage to the adjacent organs was observed. To our best knowledge, this is the first study to evaluate the performance of the bipolar system in RFA of the adrenal gland. RFA using the new bipolar ablation system is safe and produces a sufficient coagulation area to treat APAs.

Safety and feasibility of radiofrequency ablation using bipolar electrodes for aldosterone-producing adenoma: a multicentric prospective clinical study

Evaluation of feasibility and safety of percutaneous radiofrequency ablation using bipolar radiofrequency devices in a prospective multicenter cohort of patients with benign aldosterone-producing adenoma. A total of five institutions participated. CT-guided percutaneous RFA was performed for patients diagnosed as APA. The safety of the procedure was evaluated using the Common Terminology Criteria for Adverse Events. During the 84-day follow-up period, serial changes in plasma aldosterone concentration and plasma renin activity were measured. The percentage of patients with normalized hormonal activity after the procedure, was calculated with 95% confidence intervals. Forty patients were enrolled, and two patients were excluded for cerebral hemorrhage and no safe puncture root. In another patients, RFA was tried, but an intraprocedural intercostal arterial injury occurred. Consequently, RFA was completed in thirty-seven patients (20 men, 17 women; mean age, 50.4 ± 10.0 year). The tumor size was 14.8 ± 3.8 mm. The treatment success rate of the ablation was 94.6% (35/37), and a 2nd session was performed in 2.7% (1/37) patients. Grade 4 adverse events were observed in 4 out of 38 sessions (10.5%). The normalization of plasma aldosterone concentration or aldosterone-renin ratio was 86.5% (72.0–94.1: 95% confidence interval) on day 84. Percutaneous CT-guided RFA for APA using a bipolar radiofrequency system was safe and feasible with clinical success rate of 86.5% on day 84.

Percutaneous image-guided radiofrequency ablation for adrenal tumours: a systematic review

AIM

To undertaken a systematic review of the technical success and technique efficacy rates of percutaneous image-guided radiofrequency ablation (RFA) for adrenal tumours.

MATERIALS AND METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the electronic databases MEDLINE, EMBASE, and PubMed were searched for relevant studies from inception to the third week of January 2020. Only studies reporting effectiveness rates of percutaneous RFA for adrenal tumours were included. Data regarding sample size, tumours, effectiveness rates, outcomes, and complications were extracted in duplicate and recorded.

RESULTS

A total of 15 studies evaluating 292 individuals with 305 tumours were included. Patient selection criteria included age ≥18 years, contraindication to surgical intervention, and no uncorrected coagulopathy. Cumulative technical success, primary technique efficacy, and secondary technique efficacy rates were 99%, 95.1% and 100%, respectively, indicating optimal immediate control of adrenal tumours. Technical success and technique efficacy rates of primary adrenal tumours were higher than adrenal metastases; however, formal statistical analyses were precluded due to lack of comparative studies. Local tumour progression rates for adrenal metastases were 20.3% at 3 months, 26.3% at 6 months, and 29.3% at 12 months. Overall survival rates for adrenal metastases were 81.8% at 6 months, 59.6% at 12 months, and 62.9% at 18 months. The intraprocedural complication rate was 30.2%, with the most frequency reported complication being procedural hypertensive crisis.

CONCLUSION

The findings of this study suggest percutaneous image-guided RFA is a safe and efficacious procedure. Further studies are warranted to define patient selection criteria and long-term outcomes.

Comparison of the radiofrequency ablation versus laparoscopic adrenalectomy for aldosterone-producing adenoma: a meta-analysis of perioperative outcomes and safety

Radiofrequency ablation (RFA) has emerged as a new treatment for primary aldosteronism owing to aldosterone-producing adenoma (APA). We aimed to compare the perioperative outcomes and safety of RFA and laparoscopic adrenalectomy (LA) for patients with APA. We searched PubMed, EMBASE, and the Cochrane Library for all literatures published from January 2001 to September 2020 to compare RFA with LA for APA. After data extraction and quality assessments, we used Review Manager 5.4.1 and STATA 14.0 to pool the data. Four retrospective studies consisting of 170 patients were obtained. Patients who underwent RFA were associated with shorter operative time (standard mean difference (SMD): -1.98, 95% confidence interval (CI): -3.86 to 0.11, P = 0.04), less intraoperative blood loss (SMD: -0.61, 95% CI: -0.96 to -0.26, P = 0.0007), and shorter hospital stay (weight mean difference (WMD): -1.40, 95% CI: -1.71 to -1.10, P < 0.00001) than those who underwent LA. No significant differences were found in the complication rate (odds ratio (OR): 0.67, 95% CI: 0.27-1.68, P = 0.39), the incidence of hypertensive crisis (OR: 3.16, 95% CI: 0.36-27.94, P = 0.30), the conversion rate (OR: 0.44, 95% CI: 0.04-4.32, P = 0.48) or the treatment success rate (OR: 0.72, 95% CI: 0.22-2.39, P = 0.59) between the two groups. RFA could achieve clinical outcomes that approach LA for patients with APA but result in shorter operative time, less intraoperative blood loss, and shorter hospital stay. However, RFA does not appear to be able to replace the LA. Future prospective randomized trials are needed to validate these results.

Thermal ablation in adrenal disorders: a discussion of the technology, the clinical evidence and the future

PURPOSE OF REVIEW

To summarise the emerging role of thermal ablation as a therapeutic modality in the management of functioning adrenal tumours and metastases to the adrenal gland.

RECENT FINDINGS

Observational evidence has demonstrated the benefit of thermal ablation in (i) resolving adrenal endocrinopathy arising from benign adenomas, (ii) treating solitary metastases to the adrenal and (iii) controlling metastatic adrenocortical carcinoma and phaeochromocytoma/paraganglioma.

SUMMARY

Microwave thermal ablation offers a promising, minimally invasive therapeutic modality for the management of functioning adrenocortical adenomas and adrenal metastases. Appropriate technological design, treatment planning and choice of imaging modality are necessary to overcome technical challenges associated with this emerging therapeutic approach.

Ablation versus laparoscopic adrenalectomy for the treatment of aldosterone‑producing adenoma: a meta-analysis

PURPOSE

To assess the relative clinical efficacy and safety of ablation and laparoscopic adrenalectomy (LA) for the treatment of adrenal aldosterone-producing adenoma (APA).

MATERIALS AND METHODS

Pubmed, Embase, and Cochrane Library databases were searched for relevant studies, while the meta-analysis was performed with RevMan v5.3.

RESULTS

After initially identifying 496 potentially relevant studies, five were ultimately included in the final meta-analysis. In total, these studies contained 128 patients that underwent LA and 91 patients that underwent ablation to treat APA. Clinical success rates were comparable between these two groups (OR: 0.55, P = 0.20), whereas the pooled decreases of systolic and diastolic blood pressure were significantly larger in the ablation group (P = 0.01 and 0.002, respectively). Pooled changes in the aldosterone-to-renin ratio (ARR), serum potassium levels, and medication use were similar in both groups (P = 0.62, 0.24, and 0.96, respectively). The average operative duration in the ablation group was somewhat shorter, but the difference was not significant (MD: - 57.99; P = 0.05), whereas the average blood loss and postoperative hospital stay duration of patients in the ablation group were decreased for patients in the ablation group compared to the LA group (P < 0.00001 and 0.00001, respectively). Major complication, minor complication, and hypertension crisis rates were comparable between these groups (P = 0.35, 0.69, and 0.09, respectively).

CONCLUSIONS

Ablation offers comparable efficacy to LA when treating patients with APA, but is associated with a reduced operative duration, decreased intraoperative blood loss, and faster postoperative recovery.

Asian Conference on Tumor Ablation Guidelines for Adrenal Tumor Ablation

Thermal ablation is a good alternative treatment in patients who are unable to undergo adrenalectomy. Even though the Asian Conference on Tumor Ablation (ACTA) has been held for many years, adrenal ablation guidelines have not been established. No guidelines for adrenal ablation are established in American and European countries, either. The aim of this review was to introduce the first version of ACTA guidelines for adrenal tumor ablation.

Radiofrequency ablation for adenoma in patients with primary aldosteronism and hypertension: ADERADHTA, a pilot study

OBJECTIVE

To evaluate the efficacy and the feasibility of radiofrequency ablation to treat aldosterone-producing adenomas.

METHODS

In an open prospective bicentric pilot study, patients with hypertension on ambulatory blood pressure measurement, a primary aldosteronism, an adenoma measuring less than 4 cm, and confirmation of lateralization by adrenal venous sampling were recruited. The primary endpoint, based on ABPM performed at 6 months after the radiofrequency ablation, was a daytime SBP/DBP less than 135/85 mmHg without any antihypertensive drugs or a reduction of at least 20 mmHg for SBP or 10 mmHg for DBP.

RESULTS

Thirty patients have been included (mean age = 51 ± 11 years; 50% women). Mean baseline daytime SBP and DBP were 144 ± 19 / 95 ± 15 mmHg and 80% received at least two antihypertensive drugs. At 6 months: 47% (95% CI 28-66) of patients reached the primary endpoint, mean daytime SBP and DBP were 131 ± 14 (101-154)/87 ± 10 (71-107) mmHg; 43% of them did not take any antihypertensive drug and 70% of them did not take potassium supplements. Few complications were recorded: four cases of back pain at day 1 postablation; three limited pneumothoraxes, which resolved spontaneously; one lesion of a polar renal artery.

CONCLUSION

Radiofrequency ablation for hypertensive patients with aldosterone-producing adenomas seems to be an emerging promising alternative to surgery. Its efficacy and its feasibility have to be confirmed in a larger sample of patients.

Percutaneous Adrenal Radiofrequency Ablation: A Short Review for Endocrinologists

Image-guided radiofrequency ablation (RFA) has been accepted as a minimally invasive treatment for adrenal tumors in patients who are unable to undergo adrenalectomy. Accordingly, this treatment has become more readily available for treating functioning or non-functioning adrenal masses. Thus, endocrinologists need a better understanding of percutaneous RFA of adrenal tumors. The purpose of this review is to briefly describe the basic mechanism of RFA, indications and contraindications, patient preparation prior to RFA, type of complications, how to avoid complications, RFA procedures, and treatment outcomes.

Percutaneous Bilateral Adrenal Radiofrequency Ablation in Severe Adrenocorticotropic Hormone-dependent Cushing Syndrome

Objectives:

The objectives of the study were to evaluate adrenal radiofrequency ablation (RFA) as a method of treatment in patients with severe adrenocorticotropic hormone (ACTH)-dependent Cushing syndrome, among whom bilateral adrenalectomy is not a suitable option.

Material and Methods:

Five patients with ACTH-dependent Cushing syndrome underwent RFA of both adrenal glands. Four of them presented with Cushing disease unsuccessfully treated with pituitary surgery and medical therapy, while one patient had ACTH-dependent Cushing syndrome due to pancreatic endocrine tumor with liver metastases. All patients were disqualified from adrenalectomy due to morbid obesity or lack of consent.

Results:

A technical success was obtained in all cases, with only one re-intervention necessitated by a cooling effect of the inferior vena cava. Despite pre-procedural adrenergic blockade, severe hypertension was noted during the procedure in three cases, this being treated immediately using direct-acting vasodilators. No complications occurred otherwise. In all cases, significant improvement of clinical symptoms was observed, as well as marked decreases in levels of serum cortisol, free urine cortisol, and dehydroepiandrosterone sulfate.

Conclusion:

Bilateral RFA under CT-guidance is technically feasible and clinical improvement can be achieved using the method. In patients disqualified from adrenal surgery, RFA might be considered as an alternative method of ACTH-dependent Cushing syndrome treatment.

"How We Do It" - A Practical Approach to Percutaneous Adrenal Ablation Techniques

Incidental adrenal masses are common and are found in 4% of the CT scans.¹ While clinical history, laboratory results, and imaging characteristics are typically sufficient for diagnosis of an adrenal lesion, a biopsy is sometimes warranted. In some cases, adrenal mass ablation is subsequently indicated. This article serves as a brief but comprehensive review of preprocedural work-up and planning before an adrenal mass ablation, as well as a discussion on ablation techniques, associated challenges and solutions, and management of expected and unexpected outcomes.

The 2020 Italian Society of Arterial Hypertension (SIIA) practical guidelines for the management of primary aldosteronism

Background and aim

Considering the amount of novel knowledge generated in the last five years, a team of experienced hypertensionlogists was assembled to furnish updated clinical practice guidelines for the management of primary aldosteronism.

Methods

To identify the most relevant studies, the authors utilized a systematic literature review in international databases by applying the PICO strategy, and then they were required to make use of only those meeting predefined quality criteria. For studies of diagnostic tests, only those that fulfilled the Standards for Reporting of Diagnostic Accuracy recommendations were considered.

Results

Each section was jointly prepared by at least two co-authors, who provided Class of Recommendation and Level of Evidence following the American Heart Association methodology. The guidelines were sponsored by the Italian Society of Arterial Hypertension and underwent two rounds of revision, eventually reexamined by an External Committee. They were presented and thoroughly discussed in two face-to-face meetings with all co-authors and then presented on occasion of the 36th Italian Society of Arterial Hypertension meeting in order to gather further feedbacks by all members. The text amended according to these feedbacks was subjected to a further peer review.

Conclusions

After this process, substantial updated information was generated, which could simplify the diagnosis of primary aldosteronism and assist practicing physicians in optimizing treatment and follow-up of patients with one of the most common curable causes of arterial hypertension.

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.

Using microwave thermal ablation to develop a subtotal, cortical-sparing approach to the management of primary aldosteronism

Objective: To investigate the feasibility and efficacy of localized, subtotal, cortical-sparing microwave thermal ablation (MTA) as a potential curative management for primary aldosteronism. The study investigated with equal importance the selected ablation of small volumes of adrenal cortex while sparing adjacent cortex. Method: An in-vivo study was carried out in swine (n = 8) where MTA was applied under direct visualization, to the adrenal glands at 45 W or 70 W for 60 s, using a lateral, side-firing probe and a non-penetrative approach. Animals were survived for 48 h post-procedurally. Animals were investigated for markers of histological, immunohistochemical and biochemical evidence of adrenal function and adrenal damage by assessing samples drawn intra-operatively and at the time of euthanasia. Results: Selected MTA (70 W for 60 s) successfully ablated small adrenocortical volumes (∼0.8 cm³) characterized by coagulative necrosis and abnormal expression of functional markers (CYP11B1 and CYP17). Non-ablated, adjacent cortex was not affected and preserved normal expression of functional markers, without increased expression of markers of heat damage (HSP-70 and HMGB-1). Limited adrenal medullary damage was demonstrated histologically, clinically and biochemically. Conclusion: MTA offers potential as an efficient methodology for delivering targeted subtotal cortical-sparing adrenal ablation. Image-guided targeted MTA may also represent a safe future modality for curative management of PA, in the setting of both unilateral and bilateral disease.

The Prevalence of Primary Aldosteronism and Evolving Approaches for Treatment

Over six decades since primary aldosteronism was first described, much has been learned about its prevalence and optimal treatment. Estimates of the prevalence of primary aldosteronism have increased considerably over the years, even exceeding 20% in some populations of resistant hypertension. Even in patients with normal blood pressures, the prevalence of overt primary aldosteronism and dysregulated aldosterone production may be more common than appreciated. Emerging data support the concept that primary aldosteronism may be better characterized as a continuum of renin-independent aldosterone production, whose severity influences the clinical presentation and risk for incident cardiovascular disease. Mineralocorticoid receptor antagonists and adrenalectomy are the mainstay treatments for primary aldosteronism and have long been considered equally efficacious. However, recent data suggest that while surgical adrenalectomy can effectively reduce cardiovascular risk, mineralocorticoid receptor antagonist therapy may require a physiologic approach to optimize efficacy.

Progress in the Management of Primary Aldosteronism

Primary aldosteronism (PA) is now considered as one of leading causes of secondary hypertension, accounting for 5-10% of all hypertensive patients and more strikingly 20% of those with resistant hypertension. Importantly, those with the unilateral disease could be surgically cured when diagnosed appropriately. On the other hand, only a very limited portion of those suspected to have PA has been screened, diagnosed, or treated to date. With current advancement in medical technologies and genetic research, expanding knowledge of PA has been accumulated and recent achievements have also been documented in the care of those with PA. This review is aimed to have focused description on updated topics of the following; importance of PA screening both in the general and specialized settings and careful interpretation of screening data, recent achievements in hormone assays and sampling methods and their clinical relevance, and expanding knowledge on PA genetics. Improvement in workup processes and novel treatment options, as well as better understanding of the PA pathogenesis based on genetic research, might be expected to result in increased cure and better care of the patients.

Targeted treatment of primary aldosteronism - The consensus of Taiwan Society of Aldosteronism

BACKGROUND/PURPOSE

Even with the increasing recognition of primary aldosteronism (PA) as a cause of refractory hypertension and an issue of public health, the consensus of its optimal surgical or medical treatment in Taiwan has not been reached. Our objective was to develop a clinical practice guideline that is feasible for real-world management of PA patients in Taiwan.

METHODS

The Taiwan Society of Aldosteronism (TSA) Task Force recognized the above-mentioned issues and reached this Taiwan PA consensus at its inaugural meeting, in order to provide updated information of internationally acceptable standards, and also to incorporate our local disease characteristics and constraints into PA management.

RESULTS

In patients with lateralized PA, including aldosterone producing adenoma (APA), laparoscopic adrenalectomy is the 'gold standard' of treatment. Mini-laparoscopic and laparoendoscopic single-site approaches are feasible only in highly experienced surgeons. Patients with bilateral adrenal hyperplasia or those not suitable for surgery should be treated by mineralocorticoid receptor antagonists. The outcome data of PA patient management from the literature, especially from PA patients in Taiwan, are reviewed. Mental health screening is helpful in early detection and management of psychopathology among PA patients.

CONCLUSION

We hope this consensus will provide a guideline to help medical professionals to manage PA patients in Taiwan to achieve a better quality of care.

Adrenal obliteration by balloon-occluded retrograde venous ethanol injection in a swine model

PURPOSE

To evaluate the effects of adrenal obliteration by balloon-occluded retrograde venous ethanol injection.

MATERIAL AND METHODS

We inserted a micro-balloon catheter into the left adrenal vein of six pigs and retrogradely injected absolute ethanol (0.06 ml/kg) under balloon occlusion. Two pigs were sacrificed on day 3, 7, and 14 after the procedure, respectively. We evaluated adrenal cortical and medullary hormones of the left renal vein, venograms, magnetic resonance imaging scans obtained before and after the procedure, autopsy and microscopic findings, and the weight of the bilateral adrenal glands.

RESULTS

The hormone levels were extremely high on day 3 after the procedure. Post-procedure, partially-enhanced parenchyma and shaggy veins were observed. On the post-mortem examination, the left adrenal glands showed hemorrhage and adhesion on the third and seventh day and fatty proliferation 14 days after the procedure. Microscopic examination revealed hemorrhagic necrosis on day 3, inflammatory cell infiltration on day 7, and partial fibrosis 14 days after the procedure. The weight of the left adrenal gland on day 14 was lower than that of the right gland.

CONCLUSIONS

This procedure elicited partial adrenal infarction with a high catecholamine concentration in the left renal vein.

Long-term Results after CT-Guided Percutaneous Ethanol Ablation for the Treatment of Hyperfunctioning Adrenal Disorders

OBJECTIVES:

To evaluate the safety and long-term efficacy of computed tomography-guided percutaneous ethanol ablation for benign primary and secondary hyperfunctioning adrenal disorders.

METHOD:

We retrospectively evaluated the long-term results of nine patients treated with computed tomography-guided percutaneous ethanol ablation: eight subjects who presented with primary adrenal disorders, such as pheochromocytoma, primary macronodular adrenal hyperplasia and aldosterone-producing adenoma, and one subject with Cushing disease refractory to conventional treatment. Eleven sessions were performed for the nine patients. The patient data were reviewed for the clinical outcome and procedure-related complications over ten years.

RESULTS:

Patients with aldosterone-producing adenoma had clinical improvement: symptoms recurred in one case 96 months after ethanol ablation, and the other patient was still in remission 110 months later. All patients with pheochromocytoma had clinical improvement but were eventually submitted to surgery for complete remission. No significant clinical improvement was seen in patients with hypercortisolism due to primary macronodular adrenal hyperplasia or Cushing disease. Major complications were seen in five of the eleven procedures and included cardiovascular instability and myocardial infarction. Minor complications attributed to sedation were seen in two patients.

CONCLUSION:

Computed tomography-guided ethanol ablation does not appear to be suitable for the long-term treatment of hyperfunctioning adrenal disorders and is not without risks.

Radiofrequency ablation compared with laparoscopic adrenalectomy for aldosterone-producing adenoma

BACKGROUND

Radiofrequency ablation (RFA) is an emerging treatment for primary aldosteronism owing to aldosterone-producing adenoma. Whether RFA could be an alternative treatment to laparoscopic adrenalectomy is unknown.

METHODS

This was a retrospective comparative study in patients with aldosterone-producing adenoma undergoing either laparoscopic adrenalectomy or CT-guided percutaneous RFA between 2004 and 2012. Short-term outcomes and long-term resolution rates of primary aldosteronism (normalized aldosterone to renin ratio), hypokalaemia and hypertension (BP lower than 140/90 mmHg without antihypertensive medical therapy) were evaluated.

RESULTS

Some 63 patients were included, 27 in the laparoscopic adrenalectomy group and 36 in the RFA group. RFA was associated with shorter duration of operation (median 12 versus 124 min; P < 0·001), shorter hospital stay (2 versus 4 days; P < 0·001), lower analgesic requirements (13 of 36 versus 23 of 27 patients; P < 0·001) and earlier resumption of work (median 4 versus 14 days; P = 0·006). Morbidity rates were similar in the two groups. With median follow-up of 5·7 (range 1·9-10·6) years, resolution of primary aldosteronism was seen in 33 of 36 patients treated with RFA and all 27 patients who had laparoscopic adrenalectomy (P = 0·180). Hypertension was resolved less frequently after treatment with RFA compared with laparoscopic adrenalectomy (13 of 36 versus 19 of 27 patients; P = 0·007). Hypokalaemia was resolved in all patients.

CONCLUSION

For patients with aldosterone-producing adenoma the efficacy of resolution of primary aldosteronism and hypertension was inferior after treatment with RFA compared with laparoscopic adrenalectomy.

Comparison of radiofrequency ablation versus laparoscopic adrenalectomy for benign aldosterone-producing adenoma

PURPOSE

To retrospectively compare the safety and efficacy of radiofrequency ablation (RFA) with laparoscopic adrenalectomy (LA) in treating aldosterone-producing adenoma (APA) of the adrenal gland.

MATERIALS AND METHODS

From September 2009 to September 2013, seven patients, diagnosed with unilateral adrenal APA and underwent computed tomography (CT)-guided percutaneous RFA, were recruited in this retrospective study. Eighteen unilateral adrenal APA with the same tumor size (<25 mm) who underwent LA during the same interval were enrolled as control group. Treatment success was defined as complete tumor ablation on follow-up CT scan and normalization of serum aldosterone-to-renin ratio. We also compared "normalization ability" between RFA group and LA group. Normalization ability was defined as reduction in blood pressure, decrease in number of antihypertensive medicine use, reduction in serum aldosterone, and increase in serum potassium level.

RESULTS

There was no statistically significant demographic difference in both groups. The mean tumor size was 18 (8-25) mm in RFA and 19 (11-25) mm in LA groups, respectively. There was only one intra-procedure hypertensive crisis in the RFA group. No other complications needed further management in both groups. During an interval of 3-6 months of follow-up, the treatment success rate reached 100 % in the RFA group versus 94.4 % in the LA group. Normalization ability was statistically equivalent in the RFA and the LA group. Comparing with LA group, RFA group demonstrated with less post-operative pain (visual analog scale, 2.0 ± 1.16 vs. 4.22 ± 1.44, p < 0.001) and shorter operative time (105 ± 34 vs. 194 ± 58 min, p < 0.001).

CONCLUSIONS

CT-guided percutaneous RFA is effective, safe and is a justifiable alternative for patients who are reluctant or unfit for laparoscopic surgery for the treatment of APA.

Radiofrequency Ablation of Functioning Adrenal Adenomas: Preliminary Clinical and Laboratory Findings

PURPOSE

To evaluate clinical and laboratory findings in patients undergoing radiofrequency (RF) ablation for functioning adrenal adenomas.

MATERIALS AND METHODS

Eleven adult patients, nine with Conn syndrome and two with Cushing syndrome, underwent percutaneous computed tomography-guided RF ablation for benign adrenal neoplasms. Systolic, diastolic, and mean blood pressure and the number of classes of antihypertensive drugs used by each patient were analyzed before and 1, 4, and 12 weeks after the procedure. Serum hormone levels were analyzed within 30 days before and 12 weeks after the procedure.

RESULTS

Of the nine patients with Conn syndrome, eight showed normal serum aldosterone levels after the procedure and one patient had a nodule located very close to the inferior vena cava, resulting in incomplete ablation. The two patients with Cushing syndrome had normal serum and salivary cortisol levels after the procedure. Mean aldosterone concentration at baseline was 63.3 ng/dL ± 28.0 and decreased to 13.3 ng/dL ± 13.5 at 12 weeks postoperatively (P = .008). Systolic, diastolic, and mean blood pressures decreased significantly in the first week after the procedure (P < .001) and remained stable during further follow-up.

CONCLUSIONS

In patients with Conn syndrome or Cushing syndrome, percutaneous RF ablation of functioning adrenal adenomas may result in normalization of hormone secretion, improvement in blood pressure, and reduced need for antihypertensive drugs.

Image-guided ablation of adrenal lesions

Although laparoscopic adrenalectomy has remained the standard of care for the treatment for adrenal tumors, percutaneous image-guided ablation therapy, such as chemical ablation, radiofrequency ablation, cryoablation, and microwave ablation, has been shown to be clinically useful in many nonsurgical candidates. Ablation therapy has been used to treat both functioning adenomas and malignant tumors, including primary adrenal carcinoma and metastasis. For patients with functioning adenomas, biochemical and symptomatic improvement is achieved in 96 to 100% after ablation; for patients with malignant adrenal neoplasms, however, the survival benefit from ablation therapy remains unclear, though good initial results have been reported. This article outlines the current role of ablation therapy for adrenal lesions, as well as identifying some of the technical considerations for this procedure.

Morphologic Change in Computed Tomography of Aldosterone-Producing Adenoma after Radiofrequency Ablation

Objective

To evaluate the morphologic changes of aldosterone-producing adenoma (APA) on computed tomography (CT) before and after radiofrequency ablation (RFA) and to assess the factors that are important in determining successful complete ablation of these tumours.

Method

Between August 2004 and August 2011, 24 consecutive patients with APA undergoing CT-guided percutaneous RFA were identified from our prospective database. The pre-RFA and post-RFA CT appearances of these APAs that showed positive biochemical response were reviewed retrospectively for their 3-dimensional size, tumour volume, and CT attenuation in terms of Hounsfield units (HU). A comparison of these parameters before and after RFA was performed.

Results

In this study, there were 23 APAs in these 24 patients that showed biochemical cure of primary aldosteronism after RFA. When comparing post-RFA to pre-RFA CTs, there was no significant change in tumour size (14.5 mm vs 14.6 mm: P = .83) and tumour volume (1.55 cm3 vs 1.59 cm3; P = .41) after RFA. In nonenhanced CT images, there was no significant reduction in HU from pre-RFA to post-RFA measurements (4.4 HU vs 7.9 HU; P = .52). In contrast-enhanced CTs, there was a significant drop in HU after RFA (from 48.3 HU to 14.7 HU; P = .03). None of the included cases showed a focal region of contrast enhancement to suggest residual tumour.

Conclusion

A change in tumour size, tumour volume, and HU in nonenhanced CT were unreliable in defining radiologic treatment success. Only changes in HU in contrast-enhanced CT was useful in confirming a positive treatment response after RFA for APA.

Incidence and cause of hypertension during adrenal radiofrequency ablation

PURPOSE

To evaluate the incidence and cause of hypertension prospectively during adrenal radiofrequency ablation (RFA).

METHODS

For this study, approved by our institutional review board, written informed consent was obtained from all patients. Patients who received RFA for adrenal tumors (adrenal ablation) and other abdominal tumors (nonadrenal ablation) were included in this prospective study. Blood pressure was monitored during RFA. Serum adrenal hormone levels including epinephrine, norepinephrine, dopamine, and cortisol levels were measured before and during RFA. The respective incidences of procedural hypertension (systolic blood pressure >200 mmHg) of the two patient groups were compared. Factors correlating with procedural systolic blood pressure were evaluated by regression analysis.

RESULTS

Nine patients underwent adrenal RFA and another 9 patients liver (n = 5) and renal (n = 4) RFA. Asymptomatic procedural hypertension that returned to the baseline by injecting calcium blocker was found in 7 (38.9%) of 18 patients. The incidence of procedural hypertension was significantly higher in the adrenal ablation group (66.7%, 6/9) than in the nonadrenal ablation group (11.1%, 1/9, P < 0.0498). Procedural systolic blood pressure was significantly correlated with serum epinephrine (R (2) = 0.68, P < 0.0001) and norepinephrine (R (2) = 0.72, P < 0.0001) levels during RFA. The other adrenal hormones did not show correlation with procedural systolic blood pressure.

CONCLUSION

Hypertension occurs frequently during adrenal RFA because of the release of catecholamine.