Renal function after adrenalectomy in patients with primary aldosteronism.

Background: Although adrenalectomy is recommended for unilateral primary aldosteronism, the postoperative effects on renal function remain poorly understood. We evaluated renal function after adrenalectomy and identified risk factors for function decline.

Methods: A single-institution retrospective study included adults undergoing adrenalectomy (2002-2024) for unilateral primary aldosteronism on the basis of adrenal venous sampling. Estimated glomerular filtration rate (eGFR)% change was defined as ([baseline eGFR - postoperative eGFR]/baseline eGFR) × 100. Univariate logistic regression assessed estimated glomerular filtration rate decline <60 mL/min/1.73 m² at 12 months.

Results: Of 107 patients, the median age was 55 years and 92 (86%) had baseline eGFR ≥60 mL/min/1.73 m² before surgery. eGFR levels were available for 87 patients on postoperative day 1, 64 at 1 month, 43 at 6 months and 47 at 12 months, and eGFR declined from baseline in 37%, 58%, 74% and 66%, respectively. Median eGFR% decline was 13% on postoperative day 1, 18.2% at 1 month, 20.5% at 6 months and 20% at 12 months. One of 15 patients with baseline eGFR <60 required dialysis 3 months postoperatively. Among 92 patients with baseline eGFR ≥60, eGFR dropped <60 in 26% and 32.5% at 1 and 12 months, respectively. After eGFR decline <60 at 1 month, only 1 patient experienced recovery. Variables associated with eGFR decline <60 at 12 months were older age, lateralization index >30, and 1 month eGFR decline <60.

Conclusion: After adrenalectomy for unilateral primary aldosteronism, a significant decrease in estimated glomerular filtration rate was observed. Patients should be counseled on the high likelihood of unmasked renal impairment after adrenalectomy and estimated glomerular filtration rate monitoring is recommended for all patients.