Primary aldosteronism is characterized by hypertension, signs and symptoms of potassium depletion, suppressed plasma renin activity and increased aldosterone production, and it is based on the presence of aldosterone-producing adrenal adenomas.
Although it is of paramount importance that the diagnosis of aldosterone-producing adenomas inclusive of its localization be established prior to surgery, these adrenal adenomas are usually so small that a preoperative demonstration of the tumor is rarely succeeded by radiographical methods, which ordinarily include retroperitoneal pneumography, percutaneous bilateral adrenal phlebography, and radioactive 131I-cholesterol adrenal scinti-scann.
Even when the concentrations of aldosterone in plasmas obtained via percutaneous catheterization from the right and left adrenal veins are compared with each other, this method often fails to establish an accurate diagnosis of the localization of aldosteronomas because the specimens obtained are not fully supplied by only the adrenal glands.
A new method is therefore needed to improve the accuracy of preoperative diagnosis in order to further delineate many ambiguous cases. The new method must be capable of localizing unilateral adenomas in most cases and at times, though rarely, bilateral adenomas.
A comparison of the calculated ratio of aldosterone concentrations with the cortisol concentrations in plasmas obtained via catheterizations of right and left adrenal veins is expected to confirm the presence and localization of aldosteronomas.
In our study, aldosterone-producing adenomas were correctly located prior to operation in all of 12 patients, i.e., in 11 unilateral aldosteronomas and in one bilateral aldosteronoma. This result stemmed from a comparison of the ratio of aldosterone concentration with that of cortisol in plasmas obtained by percutaneous catheterization of the right and left adrenal veins.
In this study, the ratio of aldosterone concentration (ng/dl) to cortisol concentration (μg/dl) measured on the venous effluent from adrenal glands containing adenomas was greater than 5.0 × 10-3.
This procedure, measurements of, and calculation of the ratio of aldosterone to cortisol concentrations on specimens obtained via percutaneous bilateral adrenal vein catheterization is a definitive test for confirmation of aldosterone-producing adenoma in ambiguous cases.
