Is adrenal venous sampling necessary in all patients with hyperaldosteronism before adrenalectomy?

To evaluate whether selective rather than universal use of adrenal vein sampling (AVS) may be warranted in patients with hyperaldosteronism to characterize and lateralize disease before adrenalectomy.

Fifty-nine consecutive patients with biochemically diagnosed hyperaldosteronism underwent unilateral adrenalectomy at a single center during a 10-year period. In one group (n = 30), adrenalectomy was based on computed tomography (CT) only; in another (n = 29), it was based on CT and AVS. The indication for AVS was equivocal CT finding (n = 26) or patient request (n = 3). Outcome variables were postoperative serum potassium and aldosterone levels, number of hypertensive medications, and mean arterial blood pressure at 6 months.

Preoperatively, both groups were matched for age, years of hypertension, mean arterial blood pressure, and number of hypertensive medications. Average tumor sizes were 2 cm (range, 1-3 cm) in the CT-only group and 1 cm (range, 0-2.5 cm) in the CT/AVS group. Unilateral tumor was identified on CT in 30 patients (100%) in the CT-only group and in 17 patients (59%) in the CT/AVS group (P < .05). Postoperatively, aldosterone levels were lower in the CT-only group (6.3 ng/dL +/- 5.9 vs 13.5 ng/dL +/- 16; P < .05). Both groups had similar improvements in mean arterial blood pressure at 6 months (92 mm Hg +/- 12 vs 96 mm Hg +/- 9; P = .14), reductions in number of hypertensive medications (to 1.1 +/- 1.3 vs 1.2 +/- 1.1; P = .4), and improvements in hypokalemia (3.8 mEq/L +/- 0.5 vs 3.8 mEq/L +/- 0.5; P = .5).

The clinical impact of adrenalectomy was similar in both groups. CT can be used to reliably diagnose adenomas larger than 1.0 cm. AVS should be used when CT findings are equivocal or both adrenal glands are abnormal.