How to investigate neurovesical dysfunction in children with anorectal malformations

Neurovesical dysfunction (NVD) is common in children with anorectal malformation (ARM). NVD is mainly related to tethered cord or iatrogenic injury but how to investigate it is still debated. We evaluate the usefulness of routine magnetic resonance imaging (MRI) and urodynamics (UDS) for ARM.

A total of 89 children were screened for sacral, spinal or urological anomalies using sacrum x-ray, MRI, renal and spinal ultrasound, uroflowmetry and/or 4-hour voiding observation. UDS was performed in 60 patients with suspected NVD. Mean +/- SD followup was 9.8 +/- 5.2 years.

Of the 89 patients 29 presented with urinary tract anomalies. The prevalence of sacral (53 cases) and spinal cord (54) anomalies was no different between patients with low, intermediate and high ARM. Spinal cord tethering was present in 13 patients with a normal sacrum x-ray. NVD was found in 31 of the 89 patients (hyperreflexia 21 and hypo-areflexia 10), and was associated with sacral and spinal anomalies in 23, occult spinal dysraphism without bone lesion in 3 and sacral anomalies in 5. The incidence of NVD was 40% of cases with low and 51% with high ARM.

Because tethered cord occurs in children without sacral anomalies as well as in those with low ARM, we recommend evaluation of all patients using MRI. When MRI is positive UDS should be performed. We agree with a previous suggestion to evaluate all males with rectourethral fistula and females with cloaca malformations. Finally we recommend a noninvasive evaluation for all other children and UDS when neurogenic dysfunction is suspected.