Baseline Renal Volumes in Children Born With Cloacal Anomalies

Objective To better understand why children born with cloacal anomalies are at a high risk of renal insufficiency, this study aims to determine baseline renal volume in children with cloacal anomalies compared to controls. We hypothesized children with cloacal anomalies would be born with less renal volume. Methods An IRB approved database of children with cloacal anomalies was reviewed. Controls were female patients with two-vessel umbilical cord or preauricular tags who underwent screening renal ultrasound. Children were included if they had a renal ultrasound in the first 3 months of life. Cloacal exstrophy, horseshoe and cross-fused ectopic kidneys were excluded. Total and individual kidney volumes were compared between the two groups. Results The study cohort consisted of 109 patients, 46 (42.2%) cloaca patients and 63 (57.8%) controls. In unadjusted analyses, average total renal volume for cloaca and control patients was 22.4 cm3 versus 25.5 cm3 respectively (p=0.1006), and there was no significant difference when adjusting for age (p=0.3915). The estimated difference in renal unit volume between cloaca patients without solitary kidneys and controls was -1.6 cm3 (95% C.I.: -3.6, 0.4; p=0.1201), and there was no significant difference when adjusting for age (p=0.4725). The age-adjusted difference in renal unit volume between cloaca patients with solitary kidney and controls was 1.8 cm3 (95% CI: -1.1, 4.8; p=0.2148). Conclusions Children with cloacal anomalies have similar baseline renal volumes as children without cloacal anomalies. Therefore, the increased risk of renal insufficiency in this patient population appears to be due to renal injury post-natally.