Reversible suppression of the renin-aldosterone axis after unilateral adrenalectomy for adrenal adenoma

Reduced adrenocortical (aldosterone and cortisol) and adrenomedullary (adrenaline) secretory mass after unilateral adrenalectomy for aldosterone-producing adenoma has been associated with long-term hypotension (more than 2 years) in some studies. In these patients, cortisol and aldosterone levels are low, whereas plasma renin activity is high. Other studies suggest that normotension and normal plasma renin activity and serum aldosterone and cortisol levels are achieved in 60% to 87% of the patients without evidence of decreased adrenal mass, whereas the remaining patients may continue to have hypertension. We report a unique case in which unilateral adrenalectomy for adrenal adenoma was followed by severe hyperkalemia, marked volume depletion and undetectable plasma renin activity, and serum aldosterone, suggesting marked, chronic suppression of the renin-aldosterone axis. One year later, a gradual return to normokalemia, normotension, and normal plasma renin activity and aldosterone levels was achieved, indicating resolution of the suppression of the renin-aldosterone axis. Patients undergoing unilateral adrenalectomy for aldosteronoma should be followed up closely after unilateral adrenalectomy of adrenal adenoma to avoid life-threatening hyperkalemia and severe intravascular volume depletion.