Aldosterone producing adenoma: fludrocortisone suppression and left adrenal vein catheterisation in definitive diagnosis and management.

Summary: In 12 (eight female) consecutive patients with primary aldosteronism (1971–1978), aged 15 to 54 years, the diagnosis was unsuspected until hypokalaemia (mean 2.2 mmol/l) was revealed by routine biochemical testing. In nine patients, hypertension was severe (diastolic blood pressure > 120 mmHg, seven on treatment). A firm diagnosis of primary aldosteronism was based on sequential demonstration of (1) high urine potassium excretion with concurrent unexplained hypokalaemia, (2) inappropriately suppressed plasma renin activity after application of two potent stimuli to renin secretion, namely, salt-free diet and upright posture, (3) inappropriately high aldosterone production demonstrated by measurement of 24-hour urine aldosterone excretion after seven days of high salt diet and fludrocortisone acetate orally. Left adrenal vein catheterisation, which is said to provide preoperative localisation of aldosterone producing adenoma to the right or left gland and to distinguish aldosterone producing adenoma from bilateral hyperplasia of the zona glomerulosa, was successful in ten of 12 patients. A left-sided adenoma was correctly predicted in eight, a right-sided adenoma in one and results consistent with bilateral hyperplasia were found in one patient. Right-sided adenomas were present in the two patients in whom adrenal vein catheterisation was unsuccessful. After removal of the 11 adenomas, plasma potassium returned to normal and hypertension was cured in nine patients and markedly improved in two. These results show that the combination of seven days of salt loading and fludrocortisone acetate to firmly establish the diagnosis, followed by adrenal venous catheterisation to lateralise the tumour, leads to a high cure rate in the treatment of aldosterone producing adenoma.