Functional outcomes after pyeloplasty in solitary kidneys: structured analysis with the implication of Acute Kidney Injury Network (AKIN) staging criteria to predict long‐term renal function recoverability

Objectives To assess the long‐term functional outcomes after pyeloplasty in solitary kidney (SK) models and to define factors affecting postoperative renal function recoverability in adults. Patients and Methods We retrospectively evaluated all adult patients who underwent pyeloplasty for pelvi‐ureteric junction obstruction (PUJO) in SK. Long‐term renal function was assessed by diuretic scintigraphy and morphological changes were also determined, e.g. renal parenchymal volume (RPV) and parenchymal thickness (PT). We considered a >20% increase in glomerular filtration rate (GFR) as improvement, >20% decrease as deterioration, and changes within 20% as stationary renal function. Univariate and multivariate analysis for factors affecting renal function recoverability, including the Acute Kidney Injury Network (AKIN) Staging System postoperatively, were performed. Results The study included 62 patients with a mean (SD) age of 29 (10.5) years. At a median of 48 months, the mean (SD) GFR increased from 41.3 (17) to 48.5 (20.1) mL/min (P