dromlakhani Determine when AVS can be bypassed for suspected unilateral PA
STEP 1 — Gather Information
Collect age, serum potassium, plasma aldosterone concentration (PAC), and adrenal CT to assess for unilateral adrenal tumor.
STEP 2 — Rule In / Rule Out
Is the patient younger than 35 years? If no, proceed to adrenal venous sampling (AVS) for lateralization (cannot bypass). If yes, continue to evaluate for hypokalemia, high PAC, and unilateral tumor.
STEP 3 — Classify or Stratify
Among patients <35 years, assess for serum potassium <3.5 mEq/L, PAC >300 pg/mL, and unilateral adrenal tumor on CT. If all three are present, classify as high probability unilateral PA and eligible for AVS bypass; if any criterion is missing, classify as needing AVS.
STEP 4 — Decide
If classified as high probability unilateral PA, proceed to unilateral adrenalectomy after obtaining informed consent; otherwise, perform AVS to lateralize disease before deciding on surgery or medical therapy.
Clinical Guardrails / Mimics / Pitfalls
Do not bypass AVS in patients aged 35 years or older, with normokalemia (K+ ≥3.5 mEq/L), PAC ≤300 pg/mL, bilateral or absent adrenal lesions on CT, or when autonomous cortisol co‑secretion is suspected (requires dexamethasone suppression test). Avoid bypass if patient declines surgery or has high surgical risk; AVS remains gold standard for subtype diagnosis when certainty is low.
Concrete Clinical Example
A 32‑year‑old woman with hypertension presents with spontaneous hypokalemia (K+ 3.0 mEq/L), PAC 350 pg/mL, and a 1.2 cm left adrenal nodule on CT without contralateral lesion. She meets all criteria (<35 y, hypokalemia, high PAC, unilateral tumor) and, after informed consent, undergoes left laparoscopic adrenalectomy without prior AVS.
Source: Japan Endocrine Society clinical practice guideline for the diagnosis and management of primary aldosteronism 2021, Japan Endocrine Society, 2021