Associated urologic anomalies in children with solitary kidney

The aim of this study was to investigate the incidence, nature, surgical treatment, and outcome of associated urologic anomalies (AUA) in children with anatomic or functional solitary kidney (SK).

In this study, SK was defined as the kidney that is present in cases of unilateral renal agenesis (RA), or the kidney that is contralateral to a kidney that is nonfunctional secondary to either noncystic dysplastic kidney disease (NCDK), or multicystic dysplastic kidney disease (MCDK). Fifty-seven consecutive patients with SK (17 owing to RA, 10 owing to NCDK, 30 owing to MCDK) were reviewed.

A total of 23 of 57 (40%) had AUA in the SK (11 of 17 [65%] of RA cases; 7 of 10 [70%] of NCDK cases; and 5 of 30 [17%] of MCDK cases). The incidence of AUA in MCDK was significantly lower than that in RA or NCDK (p <.01: Mann-Whitney U test). Surgery was performed on 20 of 23 (87%) for vesicoureteric reflux (VUR) in 13, pelviureteric junction stenosis in 3, and ureterovesical junction stenosis in 4. Surgery was not performed in 3 of 16 with VUR because the VUR that was present was of low grade. AUA-related symptoms such as urinary tract infection and abdominal mass were seen in 15 of 23; the remaining 8 were asymptomatic. Mean age at surgery was 4.8 years. There were no operative or postoperative complications, and all cases are well without impaired renal function or hypertension after a mean follow-up period of 5.3 years.

In patients with SK, 40% had AUA in the renal collecting system of the SK. All children with SK should undergo a screening voiding cystourethrography (VCUG) even in the absence of hydronephrosis or UTI, and early recognition and treatment are imperative to decrease the long-term risk for renal damage.