Discrepant results of adrenal venous sampling in seven patients with primary aldosteronism

Adrenal venous sampling serves as a discrimination between uni- and bilateral forms of primary aldosteronism (PA). Even correctly performed adrenal venous sampling may lead to non-diagnostic results in some cases.

We describe 7 subjects with PA in whom correct cannulation of adrenal veins (high selectivity index defined as cortisol((adrenal))/cortisol((periphery)) ratio) was associated with aldosterone (ALDO) suppression (ALDO/cortisol((adrenal))/ALDO/cortisol((periphery)) ratio <1) in the left adrenal gland and in whom all subjects underwent a successful adrenalectomy on the right side. In 3 subjects, samples from the right side with lower selectivity indexes (1.11-1.7) compared to those samples with a higher index of selectivity (10.4-44.9) pointed to lateralization. Next, 2 subjects were operated because of relatively large adrenal masses in the right adrenal gland on CT despite ALDO suppression on this side. One subject presented with high selectivity indexes from the right side (19.5 and 37.6), but only one sample showed ALDO secretion. Patient 7 was treated with right-sided adrenalectomy despite a low lateralization index (ALDO/cortisol((right))/ALDO/cortisol((left)) 1.78).

Our results document some uncertainties in interpreting results of adrenal venous sampling in subjects with PA which may result from deep catheter insertion, anomalous venous drainage, or fluctuations in ALDO secretion.