Lateralisation of aldosterone-producing adenoma in primary aldosteronism

Four lateralizing methods were carried out in 14 patients with primary aldosteronism (PA): ultrasonography, CT scan, adrenal scintiscan and determination of adrenal venous aldosterone levels. In all cases, unilateral aldosterone-producing adenomas were verified by surgery. Of four lateralizing methods, determination of adrenal venous aldosterone, in spite of high diagnostic value, has two big problems: difficulty in selective catheterization of right adrenal vein and dilution of adrenal vein efflux from non-adrenal sources. To solve these problems, cortisol (C, micrograms/dl) levels along with aldosterone (A, ng/dl) were determined in samples from the left adrenal vein (LAV) and the inferior vena cava (IVC) in 8 patients with PA, and the (LAV A/C)/(IVC A/C) ratio was calculated. That ratio was also obtained in 7 patients with other types of hypertension for comparison. Accuracy of lateralisation by ultrasonography, CT scan and adrenal scintiscan was 23%, 64% and 69% respectively, in the first studies. Those rates changed to 23%, 93% and 85% when the second studies were performed. Venous blood was obtained from both adrenal veins in 46% (6/13), while lateralisation of adenoma was also predicted in 46% (6/13) by the measurement of aldosterone concentrations alone. On the other hand, (LAV A/C)/(IVC A/C) ratios were 3.54-6.98 in the cases of left APA, 0.15-0.98 in those of right APA and 1.10-2.86 in cases of other types of hypertension. There was no overlap of ratios among the three groups, resulting in correct prediction of lateralisation in all cases (8/8) of APA.(ABSTRACT TRUNCATED AT 250 WORDS)