Adrenal Vein Sampling

What is Adrenal Vein Sampling and how is it performed?

Some patients diagnosed with primary aldosteronism who are considering surgery for treatment may be referred for adrenal vein sampling. This procedure is performed by an interventional radiologist. With sedation and local anesthetic, catheters are introduced into one or both femoral veins in the upper thigh. The catheters are advanced into the inferior vena cava (large vein running the length of the abdomen that brings blood from the legs and abdomen back to the heart) at the level of the renal veins (drain blood from the kidneys into the inferior vena cava). Catheters are advanced into both the right and left adrenal vein. The right adrenal vein brings blood from the right adrenal gland directly into the inferior vena cava. The left adrenal vein drains blood from the left adrenal gland into the left renal vein. Blood and hormones from the left adrenal gland then travel a short distance and empty into the inferior vena cava. 

During adrenal vein sampling, once the catheters are in place in the adrenal veins, blood samples for aldosterone and cortisol are taken simultaneously from both adrenal veins and the inferior vena cava. In some centers, sampling may be done before and after a certain medication is given which will stimulate the adrenal gland to produce certain hormones. 

Once the procedure is completed, patients generally need to stay in the recovery area and lie flat for several hours to prevent a hematoma (collection of blood at the catheter insertion site) and are then discharged home the same day.  Results of the blood tests are then reviewed to determine if one or both adrenal glands are producing too much aldosterone. High hormone levels from one gland and not the other suggests unilateral (single-side) disease. If the blood levels are about the same on both sides, then both adrenal glands are likely producing too much aldosterone. Interpretation of these results can be complicated, and especially so if one of the catheters cannot enter into one of the adrenal veins. Your doctor will review the test results with you. In general, surgery will be offered to patients who have evidence of production of excess aldosterone coming from one gland. Treatment with medication is generally offered to those patients who are not candidates for surgery (too many other medical problems or simply don’t want surgery) and who have evidence of excess aldosterone secretion coming from both adrenal glands as removal of both adrenal glands is undesirable in most situations.