Development of novel nomograms to predict renal functional outcomes after laparoscopic adrenalectomy in patients with primary aldosteronism

Most patients with primary aldosteronism (PA) show a significant decrease in kidney function after surgery. Glomerular hyperfiltration peculiar to PA can mask mild renal failure before surgery. The aim of this retrospective study was to investigate postoperative renal functional outcomes in PA patients from different viewpoints and to develop novel nomograms that can predict renal functional outcomes in PA patients after surgery. 130 Japanese PA patients treated by unilateral laparoscopic adrenalectomy were retrospectively surveyed. Pre- and postoperative changes of estimated glomerular filtration rates (eGFRs) and the distribution of eGFR classification were compared. Furthermore, predictors of the following renal functional outcomes were investigated: (I) the percentage decrease > 25% in eGFR and (II) the presence of new-onset eGFR < 45 ml/min/1.73 m(2). Finally, two nomograms that predicted postoperative renal functional outcomes were developed and internally validated. At 6 months, the average decrease in eGFR was 16.7 mL/min/1.73 m(2) (corresponding percent decrease: 19.7%). Upstaging of eGFR classification was observed in 54.6% of patients. Age, potassium, plasma aldosterone concentration, and initial eGFR were incorporated into a nomogram predicting a > 25% postoperative decrease in eGFR. Duration of hypertension and initial eGFR were incorporated into a nomogram predicting new-onset eGFR < 45 ml/min/1.73 m(2). The value of the area under the receiver operating characteristics curve for each nomogram was 0.82 and 0.74, respectively. The first nomograms that can predict postoperative renal outcomes in PA patients were developed. They will help clinicians calculate the probability of renal dysfunction in PA patients after laparoscopic adrenalectomy.