Introduction:
Solitary kidney (SK) is the result of unilateral renal agenesis (URA) or congenital nonfunctional one kidney (e.g., a multicystic dysplastic kidney). Compensatory hypertrophy at existing kidney occurs in time and this could be as functional and structural hypertrophy. The aim of the study was determine kidney growth, renal functions, proteinuria, blood pressure and somatic growth of children with SK.
Material and methods:
Twohundred ten children aged between one and 18 yearsold with SK were included in study. Age, gender, height, weight, body surface area, maternal and paternal height, target height, blood pressure, serum urea and creatinine, glomerular filtration rate with Schwartz formula, spot urine microalbumin/creatinine ratio, kidney length (KL) and parenchymal thickness (PT) of SK in USG were recorded.
Results:
URA group consisted from 128 children and 40 of them excluded from study for concomitant urologic and other diseases (vesicoureteral reflux 11, hydronephrosis 7, posterior urethral valve 4, others 18). Multicystic dysplastic kidney (MCDK) group consisted from 82 children also 34 children excluded (vesicoureteral reflux 14, hydronephrosis 9, posterior urethral valve 1, others 10). Data from 136 children with SK was used for analysis. Male: Female ratio was 1.8 and an average age was 96±58 months. SK was found right side in 62 and left side in 74 children. Somatic growths of all children were found normal according to target height (adjusted Z score 0.14±1.35). RL (Z score 2.80±2.46) and PT (Z score 1.50±2.89) of SK was found increased. RL was well correlated with age (r=0.83), body surface area (r=0.86), and height (r=0.89). An expected equation of RL of SK (mm) = 26.7+0.6 X Height (cm) was found in regression analysis. Also PT was correlated with age (r=0.51), body surface area (r=0.53), and height (r=0.53). Renal parenchymal thickness Z score was significantly low in MCDK group than URA group (1.88±3.16 vs. 0.79±2.16, p=0.036). All of patients had normal blood pressure (<90 percentile). Decreased GFR was found 5 (3.6%) children. Microalbuminuria was found only one (0.7%) and proteinuria was found 29 (21.3%) children.
Conclusions:
SK had an increased in kidney length. KL and PT was well correlated with height. PT growth is better in URA group than MCDK group. Somatic growth of these children was not affected. Low frequency of microalbuminuria with high frequency of proteinuria suggested tubular proteinuria. Children with solitary kidney should be monitored lifelong for renal function, hypertension and proteinuria.
