Endocrine Abstracts

Adrenal venous sampling plays a central role in discriminating between unilateral (mostly aldosterone-producing adenoma) and bilateral adrenal disease (mostly bilateral hyperplasia) in primary aldosteronism. Although computed tomography or magnetic resonance are used to visualize adrenal glands, both method are not sensitive enough to detect small tumors and they are not also specific for autonomous aldosterone production. With increasing age, prevalence of adrenal tumors or nodules is increasing reaching up to 7% in the age of 70. According recent Recommendations for diagnosis and treatment of primary aldosteronism, all subjects who agree with adrenalectomy should undergo adrenal venous sampling to exclude incorrect subtype diagnosis.

To cannulate adrenal veins, in particular the right adrenal vein, skilled radiologist is essential due to difficult sampling. In the last time, visualization of right adrenal vein using the multi-detector computed tomography and rapid cortisol assays have been shown to increase the rate of successful cannulation of the right adrenal vein.

Although adrenal venous sampling is regarded method of choice, they exist according many authors uncertainties in using ACTH to stimulate the adrenal cortex in order to increase the success rate in cannulation of adrenal veins. However, stimulation of the non-adenomatous adrenal cortex with ACTH may be associated with the decrease of specificity. Another disadvantage of adrenal venous sampling is the absence of clear criteria for evaluating the success of adrenal vein cannulation (different cortisol_(adrenal) to cortisol_(periphery) ratios), and lateralization (different aldosterone_{(one side)}/cortisol_{(one side)} to aldosterone_{(other side)}/cortisol_{(other side)} ratios).

Some centers use as an alternative to adrenal venous sampling nuclear medicine imaging – scintigraphy using noriodocholesterol or positron emission tomography with ¹¹C-metomidate both after dexamethasone suppression.