Renal function in children with a congenital solitary functioning kidney: A systematic review

Unilateral Multicystic Dysplastic Kidney Management: A National Survey

Risks of contralateral kidney abnormalities and chronic kidney disease necessitate follow-up for unilateral multicystic dysplastic kidneys (MCDK). A nationwide survey of senior UK pediatricians was conducted. Of the 60 responses obtained, 62% routinely perform a dimercaptosuccinic acid scan to confirm diagnosis. Eight percent routinely perform a cystogram to investigate contralateral vesicoureteric reflux. Sixty-two percent would routinely measure renal function (frequency ranging from once only to "every 2 years"). Twenty-five percent recalled MCDK nephrectomy being performed within the previous 5 years. Respondents voiced concerns that national guidance may result in an overcautious approach but could balance consensus and safe variation, and offer families choice and reassurance. The mean estimated cost of follow-up from birth to 18 years ranged from £258 to £3854. Results demonstrate significant variation in management, highlighting the need for a clear pathway to decrease unwanted variability and to ensure those at high risk of renal sequelae are recognized early, without undue investigatory burden.

Early diagnosis of solitary functioning kidney: comparing the prognosis of kidney agenesis and multicystic dysplastic kidney

BACKGROUND

Individuals with congenital solitary functioning kidney (SFK) are at an increased risk of kidney damage. According to some studies, the risk is higher in unilateral kidney agenesis (UKA) than in unilateral multicystic dysplastic kidney (UMCDK). We hypothesized that with early detection of children with UKA and UMCDK, there would be no difference in the presence of hypertension, proteinuria, and reduced glomerular filtration rate (GFR) between UKA and UMCDK.

METHODS

Based on a long-term follow-up protocol, we evaluated a cohort of 160 children followed from birth for SFK (84 with UKA and 76 with UMCDK) detected by prenatal or routine neonatal ultrasound screening. Hypertension, proteinuria, and reduced GFR were monitored as markers of kidney damage. We compared the characteristics and outcomes of the subgroups of children with UKA and UMCDK.

RESULTS

GFR was reduced in 42 (26.2%) children, of whom 41 showed only mild reduction. Hypertension and proteinuria were found in 22 (13.8%) and 14 (8.8%) children, respectively. Combined kidney damage was present in 57 (35.6%) children. The UMCDK and UKA subgroups differed in GFR at final examination, with UMCDK patients being significantly more likely to have normal GFR compared to UKA patients (82% vs. 67%; p = 0.039).

CONCLUSIONS

One third of the children showed signs of SFK damage, albeit mild. Patients with UKA had reduced GFR significantly more often than those with UMCDK, but did not differ in the rates of hyperfiltration injury or congenital anomalies of the kidneys and urinary tract (CAKUT) in SFK.