Adrenalectomy in primary aldosteronism: a long-term follow-up study

Biomarkers to Guide Medical Therapy in Primary Aldosteronism

Primary aldosteronism (PA) is an endocrinopathy characterized by dysregulated aldosterone production that occurs despite suppression of renin and angiotensin II, and that is non-suppressible by volume and sodium loading. The effectiveness of surgical adrenalectomy for patients with lateralizing PA is characterized by the attenuation of excess aldosterone production leading to blood pressure reduction, correction of hypokalemia, and increases in renin-biomarkers that collectively indicate a reversal of PA pathophysiology and restoration of normal physiology. Even though the vast majority of patients with PA will ultimately be treated medically rather than surgically, there is a lack of guidance on how to optimize medical therapy and on key metrics of success. Herein, we review the evidence justifying approaches to medical management of PA and biomarkers that reflect endocrine principles of restoring normal physiology. We review the current arsenal of medical therapies, including dietary sodium restriction, steroidal and nonsteroidal mineralocorticoid receptor antagonists, epithelial sodium channel inhibitors, and aldosterone synthase inhibitors. It is crucial that clinicians recognize that multimodal medical treatment for PA can be highly effective at reducing the risk for adverse cardiovascular and kidney outcomes when titrated with intention. The key biomarkers reflective of optimized medical therapy are unsurprisingly similar to the physiologic expectations following surgical adrenalectomy: control of blood pressure with the fewest number of antihypertensive agents, normalization of serum potassium without supplementation, and a rise in renin. Pragmatic approaches to achieve these objectives while mitigating adverse effects are reviewed.

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.

MANAGEMENT OF ENDOCRINE DISEASE: The role of surgical adrenalectomy in primary aldosteronism

Primary aldosteronism is common and contributes to adverse cardiovascular, kidney, and metabolic outcomes. When instituted early and effectively, targeted therapies can mitigate these adverse outcomes. Surgical adrenalectomy is among the most effective treatments because it has the potential to cure, or attenuate the severity of, pathologic aldosterone excess, resulting in a host of biochemical and clinical changes that improve health outcomes. Herein, we review the role of surgical adrenalectomy in primary aldosteronism while emphasizing the physiologic ramifications of surgical intervention, and compare these to other targeted medical therapies for primary aldosteronism. We specifically review the role of curative adrenalectomy for unilateral primary aldosteronism, the role of non-curative adrenalectomy for bilateral primary aldosteronism, and how these interventions influence biochemical and clinical outcomes in relation to medical therapies for primary aldosteronism.

Aldosterone deficiency after unilateral adrenalectomy for Conn's syndrome: a case report and literature review

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We report a case of postoperative hypotension and hyperkalemia in a unilateral adrenalectomy for Conn’s syndrome.

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We highlight that there are factors that may make certain populations more at risk for developing this complication.

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Increasing awareness about this complication and its consequences highlights the needfor close monitoring in increased risk patients.

Introduction

Approximately 35% of cases of Conn’s syndrome (primary aldosteronism) result from a solitary functioning adrenal adenoma, and these patients are best managed by adrenalectomy. Postoperative hypoaldosteronism after unilateral adrenalectomy is uncommon.

Case presentation

We present a case and literature review of hypoaldosteronism after unilateral adrenalectomy for Conn’s syndrome, which demonstrates the insidious and sometimes delayed presentation.

Discussion

In this clinical case we summarize the previously published cases of post-adrenalectomy hypoaldosteronism based on a PUBMED and EBSCOhost search of all peer-reviewed publications (original articles and reviews) on this topic. A few cases of aldosterone insufficiency post-adrenalectomy for Conn’s syndrome were identified. The etiological factors for prolonged selective suppression of aldosterone secretion after unilateral adrenalectomy remain unclear.

Conclusion

It is important to be aware of the risk of postoperative hypoaldosteronism in this patient population. Close postoperative follow-up is necessary and strongly recommended, especially in patients with certain risk factors. Patients may need mineralocorticoid supplementation during this period.

Role of unilateral adrenalectomy in bilateral primary aldosteronism: a 22-year single center experience

OBJECTIVE

The aim of the study was to examine blood pressure and biochemical responses to unilateral adrenalectomy in patients with bilateral primary aldosteronism (PA) and identify predictive parameters.

CONTEXT

PA considered due to bilateral autonomous production of aldosterone is usually treated medically. Unilateral adrenalectomy has been considered ineffective. Because quality outcome data are lacking and medical treatment may cause adverse effects or fail to control hypertension, defining the role for unilateral adrenalectomy in bilateral PA is an important clinical issue.

DESIGN AND SETTING

Between 1984 and 2004, 51 of 684 patients diagnosed with bilateral PA underwent unilateral adrenalectomy. This report is based on the records of the 40 considered suitable for inclusion, who were followed for at least 12 (median, 56.4) months.

RESULTS

Hypertension was cured in 15% of patients and improved in 20%, usually within 1 yr of unilateral adrenalectomy. The proportion with controlled hypertension was significantly (P < 0.001) higher after adrenalectomy (65%) than before (25%). Mean systolic (P < 0.001) and diastolic (P < 0.001) blood pressure, left ventricular mass index (P < 0.05), plasma upright aldosterone (P < 0.05), and aldosterone/renin ratio (P < 0.001) fell. Serum creatinine independently predicted hypertension cure.

CONCLUSION

Although this retrospective analysis of patients from a single center does not permit prediction of response rates among patients diagnosed elsewhere, it suggests that unilateral adrenalectomy can be beneficial in some patients with apparent bilateral PA and should not be dismissed as a treatment option.

Long-Term Results of Adrenalectomy in Patients with Aldosterone-Producing Adenomas: Multivariate Analysis of Factors Affecting Unresolved Hypertension and Review of the Literature

The long-term surgical cure rate of patients with primary aldosteronism varies widely, and causes of persistent hypertension are not completely established. We reviewed retrospectively charts from 98 patients (range, 19–70 years old) with aldosterone-producing adenomas who underwent unilateral adrenalectomy. At a median follow-up of 81 months (range, 18–186 months), the mean blood pressure values improved in 95 out of 98 (96.9%) patients, although hypertension was cured only in 71 out of 98 (72.4%) patients. Multivariate analysis using a logistic regression model adjusted for duration of follow-up showed that only age of the patients and duration of the disease independently correlated with unresolved hypertension. The cumulative odds ratio (OR), obtained using the logistic regression function, was 5.38 (95% CI 1.78–16.22), and the OR of single variables were 1.32 (95% CI 0.36–19.83) and 4.56 (95% CI 1.41–14.78), respectively. By using discriminant analysis to derive a classification function for the prediction of unresolved hypertension, a maximum predictive power of 75 per cent was achieved. In conclusion, in patients with an aldosterone-producing adenoma undergoing surgery, the combination of age and duration of hypertension gave the best predictive power of a linear classification function and represented the main independent risk factors affecting hypertension cure rate.

Cause of residual hypertension after adrenalectomy in patients with primary aldosteronism

The cause of residual hypertension after adrenalectomy for primary aldosteronism (PA) is unknown. The purpose of this study is to investigate the characteristic pathological kidney features associated with PA. Between 1977 and 1999 at our hospital, 26 patients with PA caused by a unilateral adrenal cortical adenoma (Conn's syndrome) underwent unilateral adrenalectomy with concurrent open-wedge renal biopsy. Patients were categorized into two groups: (1) those with normotension with diastolic blood pressure less than 90 mm Hg who were not administered antihypertensive drugs, and (2) those with residual hypertension with diastolic blood pressure of 90 mm Hg or greater who were administered medication for 6 months after surgery. Thirteen patients were cured of hypertension postoperatively, and 12 patients were administered antihypertensive medications. Glomerulosclerosis, renal arteriolosclerosis, and preoperative left ventricular mass (LVM) index were worse in the group with residual hypertension than in that with normotension (17.8% +/- 7.8% versus 9.6% +/- 3.8%; P = 0.01; 2.5 +/- 0.5 versus 1.6 +/- 0.4, Bader's grade; P = 0.005; and 165 +/- 31 versus 139 +/- 24 g/m(2); P = 0.02, respectively). Severity of tubulointerstitial injury, preoperative duration of hypertension, preoperative severity of proteinuria, plasma aldosterone level, and serum potassium concentration were not significantly different between the two groups. In conclusion, severity of glomerulosclerosis and arteriolosclerosis and LVM are related to blood pressure after adrenalectomy in patients with PA.

Renal pathology in patients with primary hyperaldosteronism secondary to an adrenal cortical adenoma

OBJECTIVES

The cause of persistent hypertension following the removal of an aldosterone-producing adrenal adenoma is unknown. The purpose of this study was to determine whether this occurrence is due to existing renal histopathologic damage.

METHODS

Thirty-two patients with primary hyperaldosteronism due to an aldosterone-secreting adrenal cortical adenoma underwent open renal biopsy at the time of unilateral adrenalectomy. Biopsy results were correlated with the duration and severity of hypertension before and after surgery.

RESULTS

Nineteen patients were cured of their hypertension postoperatively, whereas 13 patients had persistent diastolic hypertension. Statistical analysis of these two groups revealed no difference when renal histopathologic variables, preoperative severity of hypertension, or preoperative duration of hypertension were compared.

CONCLUSIONS

Persistent hypertension in these patients does not appear to be due to renal histopathologic changes; coexisting essential hypertension is a more likely cause.

Primary aldosteronism. Results of surgical treatment

SUMMARY BACKGROUND DATA

Management of primary hyperaldosteronism has undergone dramatic changes in the past 40 years. This retrospective study was carried out to review our recent surgical experience and to identify potential factors associated with postoperative persistent hypertension.

METHODS

Forty-six patients who had adrenal surgery for primary hyperaldosteronism from 1983 to 1994 were included in the study.

RESULTS

Periodic paralysis occurred in 12 (26%) patients. Hypertension and hypokalemia (mean serum potassium, 2.2 + 0.5 [+ standard deviation (SD) mmol/L) were present in all patients. Postural study was diagnostic in 85% (23 of 27). Computed tomography scan correctly localized the tumor in all except 1 patient, and venous sampling was performed in 11 patients. There was no operative mortality, and complications developed in six patients (13%), including one patient requiring re-exploration for hemostasis. All patients had a histologically documented adenoma. During a mean follow-up of 51 months, 34 (77%) of the 44 patients required no further antihypertensive treatment. Two patients were lost to follow-up. Age, response to spironolactone treatment, and blood pressure on discharge were risk factors identified for persistent hypertension.

CONCLUSION

Primary hyperaldosteronism due to aldosterone-producing adenoma can be diagnosed and localized expeditiously, whereas surgical treatment can be performed safely. Hypokalemia may be cured by surgical treatment, although persistent hypertension, usually of a mild degree, still occurs in selected patients.

Bilateral aldosterone-producing adenomas in two patients diagnosed by immunohistochemical analysis of steroidogenic enzymes

Bilateral adrenal aldosterone-producing adenomas (APA) are rare. It is important to distinguish bilateral APA from idiopathic hyperaldosteronism (IHA) which is due to bilateral hyperplasia of the adrenal cortex. We present two patients with bilateral APA in whom the diagnosis was made histochemically by analyzing steroidogenic enzymes. They showed hypokalemia, high plasma aldosterone concentration (PAC) and suppressed plasma renin activity (PRA). Bilateral adrenal tumors were represented by computed tomography, and surgical resection was performed. In both cases, cytochrome P-450 and other enzymes that were involved in aldosterone synthesis were found mainly in tumor, but little in the zona glomerulosa of the adjacent adrenals, which showed paradoxical hyperplasia. Such cases are difficult to distinguish from IHA. The two disorders were differentiated by immunohistochemical analysis of steroidogenic enzymes.

Long-term treatment of mineralocorticoid excess syndromes

Recognition of the pathogenesis of secondary forms of hypertension is often considered the key to appropriate choice of treatment. We here present the results of a prolonged clinical follow-up (from 1 to 20 years) of a large number of patients with mineralocorticoid excess syndromes (MES), including over 100 patients with primary aldosteronism (PA), 3 cases with dexamethasone-suppressible aldosteronism (DSA), 3 cases of apparent mineralocorticoid excess (AME) Type II, and 4 patients with 17-hydroxylase deficiency (17OHDS). The patients with PA have been divided in two subgroups, one of 69 cases followed between 1973 and 1982, and the second of 37 patients studied between 1983 and 1992; 33 further cases were not evaluated due to poor compliance. In group I, 26 patients underwent surgery (23 unilateral adenoma, 1 primary hyperplasia, 2 bilateral nodular hyperplasia); at 5 years 50% had normal blood pressure, 25% had mild hypertension and 25% had moderate to severe hypertension. Forty-three patients with either adenoma (APA) or idiopathic aldosteronism (IHA) received long-term spironolactone treatment. Among them, 13 required the addition of thiazide and/or beta-blockers, while 13 were switched to an amiloride/thiazide combination (+/- beta blockers) due to side-effects to spironolactone (gynecomastia 6/20 males, menstrual upset or breast pain in 7/23 females). In group II, 12 patients underwent surgery (11 adenoma, 1 primary hyperplasia) with a similar outcome at 3 years as in group I; 25 patients were put on either K canrenoate (11) or Ca++ channel blockers (14) with or without KCl supplementation; in 8 cases these two drugs were combined according to blood pressure levels achieved during the follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Primary aldosteronism: difference in clinical presentation and long-term follow-up between adenoma and bilateral hyperplasia of the adrenal glands

Since 1974 primary aldosteronism has been diagnosed in 71 patients in our outpatient clinic. Thirty-four patients had a unilateral aldosterone-producing adenoma, whereas bilateral adrenal hyperplasia was diagnosed in 37 patients. Although at the time of diagnosis the mean potassium values were lower and mean aldosterone levels were higher in patients with an adenoma, as compared to those with bilateral hyperplasia, these laboratory data did not allow us to differentiate between the two leading causes of primary aldosteronism in the individual patient due to pronounced overlap of laboratory values between the two groups. During the first few years, a successful differential diagnosis was made by adrenal phlebography and separate sampling of plasma aldosterone in both adrenal veins; later non-invasive imaging techniques such as computed tomography and radionuclide scanning were used. The best results were obtained in patients with adenoma who underwent adrenalectomy. Fifty-six percent of these patients were clinically and biochemically cured; 28% were improved and had normal blood pressure values during drug treatment. In contrast, patients with bilateral hyperplasia were treated pharmacologically, but only in half of the patients could normal blood pressure values be achieved. Two thirds of the male patients developed gynecomastia during spironolactone treatment. As expected, unilateral adrenalectomy was unsuccessful in the 7 patients with bilateral hyperplasia who underwent surgery. Our results confirm that surgical treatment of adrenal adenomas and drug treatment of bilateral hyperplasias are the appropriate therapy in primary aldosteronism. A differential diagnosis cannot be made on the basis of clinical and non-invasive laboratory data alone; imaging techniques have to be included in the diagnostic process.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenalectomy in primary aldosteronism: a long-term follow-up study in 52 patients

From 1975 to 1989, 52 patients with primary aldosteronism underwent adrenalectomy. There were 16 men and 36 women. The average age was 42.5 years, ranging from 28 years to 70 years. They were all hypertensive, with average pre-operative diastolic pressures varying from 105 to 140 mm Hg (median 117 mm Hg). The subjective symptoms most frequently reported were headache (71%) and asthenia (53%). In all patients except two, serum potassium concentration was 3.3 mEq/L (median 2.7 mEq/L) at the time of diagnosis. Plasma aldosterone concentration was elevated in all patients, 48 +/- 5.3 ng/mL in the recumbent position and 52.6 +/- 6.0 ng/mL in the upright position. The operations carried out were 50 unilateral and 2 bilateral adrenalectomies. In 4 patients a transperitoneal approach was employed and in the remaining 48 patients an extraperitoneal flank incision was used. The histological findings were 47 adenomas (with dimension ranging from 1 to 4.5 cm), unilateral macronodular hyperplasia in 2 patients, an adenoma plus controlateral hyperplasia in 1 patient, bilateral hyperplasia in 1 patient, and unilateral hyperplasia in 1 patient. After long-term follow-up (median 77 months, range 13 to 189 months), 15 patients remained hypertensive (diastolic blood pressure up to 100 mm Hg). In 9 of these patients the hypertensive illness had been present for more than 5 years prior to operation. In the remaining 37 (71%) patients, the arterial pressure returned to normal and in almost half of the patients this result was evident one or two days after operation.

Primary aldosteronism. Study of twenty-six operated cases

A follow-up study of 26 patients operated on for suspicion of primary aldosteronism was made. The preoperative investigative procedures, including serum potassium concentration, urinary aldosterone excretion, and plasma renin activity, could not differentiate between patients with cortical adenomas and those with cortical hyperplasia or normal glands. Preoperative roentgenologic examinations visualized only one third of the adenomas. Altogether 44 of the 52 suprarenal glands had to be explored to reveal the 21 adenomas. Patients with cortical adenoma often became normotensive, in contrast to those with cortical hyperplasia or normal adrenal glands histopathologically. The suprarenal glands were explored from behind according to Nesbit. The complications were few and minor.

Primary aldosteronism: diagnosis and treatment

The syndrome of primary aldosteronism produces few signs or symptoms. The diagnosis should be suspected when either spontaneous hypokalemia or easily provoked hypokalemia is found in a patient with hypertension. Hypokalemia in association with inappropriate kaliuresis, low plasma renin activity, and a high plasma aldosterone concentration/plasma renin activity ratio are the findings on initial screening tests that should suggest primary aldosteronism. The diagnosis must be confirmed by demonstrating nonsuppressible aldosterone excretion in conjunction with normal cortisol excretion. The choice of therapy is based on distinguishing unilateral from bilateral adrenal disease. With a unilateral adrenal adenoma, surgical removal reverses the hypokalemia and frequently cures the hypertension. In most patients with bilateral adrenal hyperplasia who are treated surgically, however, hypertension persists; thus, the initial treatment in these patients should be pharmacologic.

Unexpected incidence of low blood pressure 2 years after unilateral adrenalectomy for primary aldosteronism

1. Serial observations of blood pressure after unilateral adrenalectomy for aldosterone-producing adenoma revealed an incidence of hypotension (systolic BP less than fifth percentile for age- and sex-matched normal population) of 27% at 2 years, more than 5 times that predicted. 2. Serial observations of volume regulatory hormones showed significantly raised mean levels of plasma renin activity consistent with hypovolaemia. Significantly reduced mean aldosterone levels despite significantly raised mean plasma renin activity levels may reflect reduced responsiveness of the remaining adrenal. 3. Reduction of significantly elevated preoperative ANP levels to significantly reduced levels postoperatively is also in keeping with postoperative hypovolaemia. 4. A 50% reduction in plasma adrenaline after unilateral adrenalectomy might contribute to reduced noradrenergic activity (prejunctional beta-receptor) and reduced blood pressure, but plasma noradrenaline did not fall significantly postoperatively. 5. Postoperative levels of renin, aldosterone, adrenaline and noradrenaline were not significantly different between those who did, and those who did not, become hypotensive.

Therapeutic value of calcium antagonists in autonomous hyperaldosteronism

The chronic effect of the calcium antagonist nitrendipine was investigated on blood pressure (BP), plasma aldosterone concentration (PAC), plasma renin activity (PRA), and serum potassium in six patients with primary aldosteronism, either due to an (unilateral) aldosterone-producing adenoma (APA; n = 3; age, 44 +/- 4 years; PAC, 312 +/- 96 pg/ml; PRA, less than 0.1 ng/l.h; serum potassium, 2.8 +/- 0.3 mmol/l) or to bilateral idiopathic hyperaldosteronism (IHA; n = 3; age, 49 +/- 1 years; PAC, 212 +/- 32 pg/ml; PRA, 0.1 +/- 0.1 ng/l.h; serum potassium, 3.3 +/- 0.2 mmol/l). After withdrawal of antihypertensive medications at least 3 weeks prior to the study, nitrendipine was given orally in a daily dosage of 40 to 60 mg. BP, PAC, PRA, and serum potassium were determined before (see data above) and after 4 weeks of nitrendipine therapy. After 4 weeks, BP was significantly reduced (178 +/- 10 to 165 +/- 6 mmHg systolic, 109 +/- 7 to 101 +/- 6 mmHg diastolic) in three patients with APA and in two with IHA. No significant changes of PAC, PRA, and serum potassium were observed in these patients. However, one patient with clinical characteristics of IHA and a long-term history of diuretic therapy showed a complete normalization of BP, PAC, PRA, and serum potassium, suggesting that the etiology of autonomous hyperaldosteronism in this patient might differ from typical primary aldosteronism. From these findings we conclude that calcium antagonists may be helpful in lowering BP in those patients with primary aldosteronism who develop intolerable side effects under treatment with spironolactone or trilostane.(ABSTRACT TRUNCATED AT 250 WORDS)