Case 1 49 yo male with hypertension on a potassium-sparing diuretic

Findings Access from right iliac vein Selection of left and right adrenal veins Gentle venography to confirm location at adrenal veins; formal venography unnecessary Subsequent bilateral adrenal vein and IVC sampling CT useful in planning by demonstrating the anatomy and position of the adrenal veins.

Why do Adrenal vein sampling??? Done to assess whether autonomous hormone production is uni or bilateral in known endocrine disease. Adrenal lesions rarely require catheter-based imaging for diagnosis; typically done with CT and MRI Most commonly performed in primary aldosteronism, which is the most common hypersecretory adrenal disease. Less commonly, in proven pheo, when no source is visible on CT or other imaging. Rarely performed in adrenal Cushing disease or syndromes of androgen excess

Aldosteronism Secreted by the adrenal cortex that induces Na retention and K excretion. A patient with diastolic HTN and K < 3.5 mEq/L is suggestive of Conn’s. May also check plasma renin, 24- hr urine In primary dz – hypersecretion by either an adenoma (2/3) or bilateral hyperplasia (1/3). <1% of cases due to carcinoma. Secondary dz – response to renal artery stenosis, CHF, pregnancy or cirrhosis. Initial imaging is with CT or MRI with angiography after definitive dx is made

Adrenal sampling Discussion Samples may be obtained before and after ACTH adm. Eval for aldosterone and cortisol, with assumption that cortisol is the same for both glands. Cortisol used to confirm adrenal vein is sampled and and to help distinguish adenoma from hyperplasia. Adenomas: ratio of aldosterone/cortisol is higher before and after ACTH (>4), whereas the ratio in the opposite gland is similar to the femoral vein. Tx for unilateral adenoma is surgical resection. Bilateral hyperplasia is managed medically as resection would result in insufficiency.

Thoughts and limitations Previously thought if aldosteronism was diagnosed and an adenoma was seen on CT then sampling was unnecessary – wrong! –Sampling v CT showed CT to be inaccurate or non- contributory in 68% for lesions <1 cm. CT value is twofold: –Allows assessment of mass lesions –Demonstrates the anatomy/position of adrenal veins Sampling limitations –Quiescent phase of aldosterone production –Venous drainage in vein other than one cannulated –Superselective sampling does not house an adenoma