Assessment of postoperative renal function after adrenalectomy in patients with primary aldosteronism

Objective To investigate kidney function change during adrenalectomy in patients with primary aldosteronism and assess predictors of kidney function decline. Methods The present study included 90 patients who underwent adrenalectomy for primary aldosteronism between 2004 and 2017. Kidney function was evaluated 1 month after surgery. Predictors associated with a ≥10% decline in the estimated glomerular filtration rate were investigated. Kidney parenchymal volume was compared before and after surgery in 10 patients using volumetric studies. Results The mean estimated glomerular filtration rate decline in the total cohort at 1 month after surgery was 13.3% (before: 72.9 mL/min/1.73 m2, after: 64.9 mL/min/1.73 m2, P < 0.0001). The mean serum plasma aldosterone concentration (before: 373 pg/mL vs after: 78 pg/mL, P < 0.0001) and potassium level (before: 3.7 mEq/L vs after: 3.9 mEq/L, P = 0.0001) were also significantly different after surgery. Age (odds ratio 6.37, P = 0.0006), preoperative plasma aldosterone concentration (odds ratio 3.12, P = 0.0209) and preoperative serum potassium level (odds ratio 2.87, P = 0.0010) were independent predictors of a ≥10% decline in estimated glomerular filtration rate. Volumetric studies in 10 patients showed that mean postoperative parenchymal volume was significantly decreased compared with the preoperative volume (263 cc vs 312 cc, P = 0.0003), with decreases in estimated glomerular filtration rate from 63 to 56 mL/min/1.73 m2 (P = 0.0146). Conclusions Kidney function deterioration after adrenalectomy can be detected in patients with primary aldosteronism. Age, preoperative plasma aldosterone concentration and preoperative potassium level are significant predictors of a decrease in the estimated glomerular filtration rate. Normal parenchymal volume decreases in line with renal functional deterioration.