Adrenal vein sampling (AVS) is a procedure where blood is collected from the adrenal veins via catheter to confirm autonomous hormone production, if it is unilateral or bilateral, and to guide further treatment 1. If unilateral, the adrenal gland can be removed by surgery; thus curing secondary hypertension in 50 to 80% of the cases that are caused by aldosterone-producing adenoma while the remaining cases show improvement in hypertension treatment 1. If bilateral, the hypertension is better controlled with specific medications 1.
On this page:
Images:
Indication
Adrenal vein sampling is commonly performed in primary aldosteronism (PA), being indicated to identify aldosterone-secreting adenomas and to differentiate adenomas from bilateral adrenal hyperplasia 1.
Less commonly, AVS is performed to identify biochemically proven pheochromocytoma when that is not visible through CT or other imaging methods 1. In rare occasions, adrenal vein sampling could be used for adrenal Cushing disease or for syndromes of androgen excess 1.
Pre-procedural assessment
Multiphase CT utilizing an adrenal protocol is performed in patients with PA to 4:
identify a fat-poor adrenal adenoma that can mimic an aldosterone-secreting adenoma
identify adrenal cortical adenocarcinoma (rare cause of PA)
assess the (middle) adrenal veins and identify venous variants relevant to the catheter approach e.g. a right adrenal vein originating from or close to an accessory hepatic vein
Technique
Although technique varies a standard modern approach would consist of 1,3:
review prior imaging as CT or MRI
obtain a venous access from common femoral vein puncture with guiding catheter / microcatheter set-up
place selective catheter in IVC and sequentially cannulate and sample right followed by left adrenal vein
the right adrenal vein arises directly from the posterior wall of the IVC at T12 level. The left adrenal vein in most cases unites with the inferior phrenic vein, forming a common trunk which drains into the left renal vein.
-
confirm catheter position with contrast injection
back pain could be reported by the patient while contrast is injected into adrenal vein, particularly on the right
-
venous sampling from each adrenal vein and peripheral source (e.g., femoral vein)
some institutions use adrenocorticotropic hormone (ACTH) infusions before and during adrenal sampling.
other institutions avoid it due a suspicion of possible misdiagnosed bilateral cases 1.
-
it may be difficult to aspirate blood from the adrenal vein, likely due to suction causing vessel wall collapse at the catheter tip. Strategies to overcome this include
use of a catheter with a single side-hole close to the tip
intermittent gentle suction
suction using a partially air-filled syringe in order to reduce suction pressure
label all tubes (attention to right vs. left)
submit samples for laboratory assays (aldosterone and cortisol)
Complications
-
unrecognised failure to select the adrenal vein.
this is most common on the right, where an accessory hepatic vein can mimic the right adrenal vein
the right adrenal gland has a variable appearance on venography
identification of emissary veins from its capsule provides increased confidence for correct vein selection
in addition, contrast injection into an adrenal vein often produces discomfort, whereas contrast injection into an accessory hepatic vein will not 1
-
adrenal vein rupture due to contrast injection
reported incidence is 4-10%
in rare causes this can lead to adrenal hemorrhage, manifested clinically by severe pain which can persist for 2-3 days, and potentially causing permanent destruction of the gland 1
other complications include hematoma, infarction, adrenal vein thrombosis and perforation, hypertensive crisis, and adrenal insufficiency 1