End stage renal disease and kidney transplant in patients with anorectal malformation: is there an alternative route?

BACKGROUND/PURPOSE: Mortality from end stage renal disease (ESRD) in patients with anorectal malformation (ARM) is reported to be between 2.5 and 6%. The risk differs depending on the type of ARM (6.4% "high" vs. 1.1% "low"). The purpose of this study was to review the characteristics of the ARM patients who received a kidney transplant (KT) to potentially identify if any modifiable factors existed that may have prevented ESRD.

METHODS: The Colorectal Center and the kidney transplant databases at Cincinnati Children's Hospital were queried to identify patients with ARM and a KT. Data obtained included: gender, type of ARM, associated characteristics, urological status at birth, surgical and medical management, age at KT, and possible interventions that could have prevented or delayed the KT.

RESULTS: 20 patients with ARM who underwent KT were identified. 16 were females, thirteen of whom had a cloaca; the average common channel length in these patients was 5 cm, ranging from 2 to 8 cm. Nine cloaca patients had hydrocolpos and 5 of them were not drained at birth. Eleven patients presented with renal failure at birth. Five patients with cloaca had common channel atresia/stenosis, 2 male patients had severe urethral atresia, 2 patients had absent bladders, and 1 patient had bilateral blind ureters. At birth, 6 patients had single functional kidneys, 4 had bilateral hydronephrosis with megaureters, 3 patients had bilateral dysplastic kidneys, 1 patient had a single kidney with hydronephrosis, and 1 patient had a single hypoplastic kidney. The average age at KT was 10.9 years (range 2-21 years.); in 3 patients, the KT was performed before the repair of the ARM. One patient died after the KT and one patient had rejection following the KT and is currently on hemodialysis.

CONCLUSION: Patients with cloaca and recto-bladderneck fistula are the type of ARM with the highest risk for ESRD. Kidney failure at birth, common channel/urethral atresia, hydrocolpos, single kidney, and ectopic ureters represent high risk for future KT. Even when missed opportunities were identified, the impact of interventions to prevent or delay the onset of ESRD could not be proven.