The effect of back closure on detrusor function in neonates with myelomeningocele

To determine the effect of back closure on the detrusor-external sphincter coordination, we reviewed the medical records of 40 neonates with myelodysplasia studied prospectively with urodynamic assessment and renal ultrasonography before closure of the spinal defect, within 7 days of closure and at 3-month intervals thereafter. Only 31 of the 40 neonates met all criteria for inclusion. All renal sonograms were normal before and after closure. Urodynamic evaluation demonstrated coordinated detrusor-sphincter activity in 18 neonates before and after closure. During prolonged followup 1 patient had detrusor areflexia and 4 had detrusor-sphincter dyssynergia. Of 11 neonates who demonstrated detrusor areflexia and no external sphincter activity before closure 10 were unchanged on initial post-closure evaluation (4 had detrusor-sphincter dyssynergia during followup), while 1 demonstrated detrusor areflexia with external sphincter overactivity and vesicoureteral reflux after closure. The latter patient subsequently had detrusor hyperreflexia, more severe reflux and upper tract deterioration. She was temporized with a cutaneous vesicostomy. One patient demonstrated detrusor-sphincter dyssynergia before closure and detrusor areflexia with no external sphincter activity after closure, the consequence of surgical division of the neural placode during back closure. The remaining patient demonstrated detrusor-sphincter dyssynergia before and after closure. This patient had coordinated detrusor-sphincter activity during followup. Those neonates who presented with or later had detrusor-sphincter dyssynergia were managed initially with neuropharmacological agents and clean intermittent catheterization. An unsuccessful outcome was managed by cutaneous vesicostomy. Our study demonstrates that neonatal closure of the spinal cord defect does not appear to affect detrusor-sphincter coordination adversely, and re-emphasizes the need for careful and regular followup in children with myelodysplasia to detect deterioration of the urinary tract.