Primary Aldosteronism: Does Underlying Pathology Impact Clinical Presentation and Outcomes Following Unilateral Adrenalectomy?

Introduction: Patients undergoing unilateral adrenalectomy for primary aldosteronism (PA) may have a solitary adenoma, unilateral hyperplasia, or multiple adenomas on final pathology. This study investigated whether the underlying pathological diagnosis was associated with differences in clinical presentation and postoperative outcomes. Methods: A retrospective cohort study of patients undergoing unilateral adrenalectomy for PA from 2004 to 2015 at our institution was performed. Baseline clinical and laboratory parameters, as well as postoperative biochemical and hypertension cure rates, were compared across the three aforementioned pathological groups. Results: Of 206 patients who met criteria for inclusion, 152 (73.8%) had a single adenoma, 33 (16%) had unilateral hyperplasia, and 21 (10.2%) had multiple unilateral adenomas. Patients with unilateral hyperplasia were more likely to be male (81.2% vs 57.9%, P =.03), undergo left-sided adrenalectomy (78.8% vs 47.4%, P <.01), and had a lower median adrenal venous sampling lateralization index (9.8 vs 19.8, P =.04) compared to those with solitary, but not multiple unilateral adenomas. No differences were seen in age, duration of hypertension, preoperative plasma aldosterone levels, plasma renin activities, 24-h urinary aldosterone excretion, serum potassium concentrations, and the number of preoperative antihypertensive medications across all three pathological groups. All patients achieved biochemical cure following adrenalectomy, and no significant differences in the rates of hypertension cure or improvement were observed in comparisons across pathological subtype. Conclusions: Clinical presentation and postoperative outcomes are similar regardless of underlying pathology in patients with PA. Because one in four patients may harbor unilateral hyperplasia or multiple adenomas, total unilateral adrenalectomy should be performed as the operation of choice over adrenal-sparing approaches.