Purpose: 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).
Methods: 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.
Results: 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.
Conclusions: 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.