A 34-year-old woman presents with hypokalemia, hypertension resistant to four drugs, and suppressed plasma renin activity. Aldosterone-to-renin ratio (ARR) is markedly elevated at 42 ng/dL per ng/mL/h. Confirmatory testing with salt loading is positive. Adrenal CT shows a 1.8 cm left adrenal adenoma. What is the next BEST step?
- A Adrenal vein sampling before surgery ✓
- B Proceed directly to laparoscopic left adrenalectomy
- C Start spironolactone lifelong without surgery
- D Repeat ARR after stopping antihypertensives
Correct answer: A. Adrenal vein sampling before surgery
Explanation
In primary hyperaldosteronism, adrenal vein sampling (AVS) is mandatory before surgery whenever the patient is an operative candidate and bilateral disease cannot be excluded — CT alone misclassifies lateralization in up to 25% of cases (confirmed by Endocrine Society guidelines). In patients under 35 with a unilateral macroadenoma on CT, some guidelines allow omitting AVS, but the standard recommendation remains AVS. Proceeding directly to surgery without AVS risks unnecessary adrenalectomy if the contralateral gland is dominant.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
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Written and medically reviewed by the StethoPrep medical team.