Genitourinary anatomy: Adrenal venous sampling

Adrenal vein sampling (AVS) can be completed with simultaneous or sequential cannulation of the adrenal veins. As shown in this image, a percutaneous femoral vein approach is used. Under fluoroscopic guidance, correct catheter tip location is confirmed with injection of a small amount of contrast medium. With gentle aspiration, blood is obtained from both adrenal veins and the external iliac vein. The right adrenal vein can be difficult to catheterize because it is small in caliber, short length, and angulated path. The short length of the right adrenal vein is problematic because it may not support a stable catheter position during respiratory motion. The left adrenal vein is a tributary of the inferior phrenic vein and the blood sample on the left is usually obtained from the common trunk of the inferior phrenic vein just proximal to the inflow from the left adrenal vein. In the sequential sampling technique, only one femoral vein puncture site is used, and the right adrenal vein is sampled first because it is usually more time consuming. Then, with a different catheter, the left adrenal vein is rapidly sampled, followed by the external iliac vein. Aldosterone and cortisol concentrations are measured from all three sites. Because absolute values are required, the blood samples should be assayed at serial dilutions: 1:1, 1:10, and 1:50. Complication rates with AVS are very low at centers with experienced interventional radiologists.