Abstract
The urological malformations associated with anorectal anomalies (ARA) are not only
anatomical, but also functional, the latter being related to congenital neurovesical
dysfunction (NVD). The true incidence of spinal dysraphism (SD) in these children
is still unclear and is probably underestimated. The concept of caudal regression
could explain its association with the anorectal anomalies.
Because of awareness of the late onset of neurovesical dysfunction and/or orthopaedic
symptoms in some of our patients, in 1991 we started to screen with magnetic resonance
imaging (MRI) the spinal cord of all patients with ARA. Eighteen (44%) out of 41 patients
without neurological or orthopaedic symptoms and 7 (78%) of 9 children with neurological
or orthopaedics symptoms screened by MRI showed pathological findings. The overall
incidence of spinal dysraphism in ARA was 50%, without any great difference with respect
to the type of the anomaly (high, low, cloacal). The pathological MRI findings encountered
were: fibrolipoma (with or without a thickened filum terminale), tethering of the
cord and syringomyelia, and sac anomalies. In order to check the onset of NVD in these
children, we performed urodynamic studies with external sphincter electromyography
in 24. Grouped by age: 14 were between 5 and 18 months and ten were 4 to 13 years
old. Ten patients (71%) out of the first group and 3 (30%) out of the second had a
normal urodynamic pattern. A total of 11 children had pathological findings; of these,
4 infants had a hyperreflexic bladder (one with detrusor-sphincter dyssynergia) suggesting
upper motor neuron (UMN) lesion. Of the 7 older patients, two had UMN and 3 lower
motor neuron (LMN) lesion. Two of the remaining children (without spinal dysraphism)
had Down syndrome and their urodynamic pattern (detrusor-sphincter incoordination)
was not conclusive for NVD.
The incidence of spinal dysraphism in children with anorectal anomalies is high and
screening with morphological studies of the spinal cord are mandatory. Neurovesical
dysfunction should be suspected in all these children and it is likely to be congenital
in nature. Early and repeated urodynamic studies are recommended to detect neurogenic
bladder dysfunction before the onset of symptoms.
Key words
Spinal dysraphism - Anorectal anomalies - Neuropathic bladder
