Are children with congenital solitary kidney at risk for lifelong complications? A lack of prediction demands caution

Abstract

Congenital solitary functioning kidney (CSFK), which develops during embryo or fetal life, means having either one anatomical/functional kidney or two kidneys, one of which does not function. Similar anomalies have been seen in every other organ system and involve a large percentage of newborns. Still, prediction of long-term renal morbidity in congenital functioning solitary kidney is complicated by the great variability of renal and extrarenal phenotypes. Classification of different solitary renal types, whether or not a syndrome, may help to predict the possible evolution of complications; this may be hindered, however, by the gene-environment role during kidney development. Since the risk of renal failure in children with CSFK depends on several variables, it is always advisable to have a precise clinical description at diagnosis. This condition often requires long-term follow-up into adulthood.

Risk Factors for Renal Injury in Children With a Solitary Functioning Kidney

“…26,27 Studies on long-term outcomes of children with an SFK have conflicting results. 8,9,[28][29][30][31][32][33][34][35][36][37][38][39][40][41] In addition, it is often stated that children with an SFK are not expected to develop renal damage, because most long-term follow-up surveys on kidney donors show an excellent prognosis. 42 However, hyperfiltration is much more pronounced when renal mass reduction occurs earlier in life, 43 which makes these situations (SFK in childhood versus uninephric kidney donors) not comparable.…”

Standardization of pediatric uroradiological terms: A multidisciplinary European glossary

“…Solitary kidney (= renal agenesis) The radiological absent kidney may correspond to a real renal agenesis or more often results from an involution of dysplastic kidney [34]. As imaging cannot determine the cause of the missing kidney (shrinkage or renal agenesis), the use of the terms "renal agenesis" is discouraged.…”

Congenital anomalies of kidney and hand: a review

“…The urinary tract anomalies account for ∼20–30% of total congenital anomalies diagnosed during pregnancy [ 3 ]. CAKUT is phenotypically variable and results in significant renal problems in adulthood ranging from hypertension, proteinuria to end-stage renal disease [ 8 ]. The spectrum of CAKUT includes kidney hypoplasia/dysplasia, renal agenesis, multicystic, horseshoe or duplex kidneys, VUR, hydroureter, hydronephrosis and obstruction at the vesicoureteric or uretero-pelvic junction [ 5 , 8 ].…”