The main determinant of upper urinary tract deterioration is the intravesical pressure, both in storage and voiding situations. A high incidence of vesicoureteral reflux and ureteral dilation (functional obstruction of the urethra) found in patients with myelomeningocele. High pressures may result from increased outlet resistance or decreased bladder wall compliance. Increased outlet resistance may be caused by sphincter dyssynergia (inability to coordinate voluntary muscle movements of the sphincter) or fibrosis of a denervated sphincter. Decreased bladder wall compliance is associated with areflexia of the detrusor. Any of these urologic dysfunctions can occur in myelomeningocele, but manifestations may vary over time because of the changing neurological status in some of these patients (Blum, 1991).

Treatment strategies are designed both to prevent deterioration of renal function and to establish infection-free social continence. These goals can be accomplished by several different methods of bladder drainage, including vesicostomy (opening of the bladder onto the anterior abdominal wall), intermittent catheterization, and placement of indwelling catheters. Long-term maintenance of low bladder pressures may require the adjunctive use of medications to reduce bladder pressures and/or decrease spastic or hypotonic sphincter function. The success rate of self-catheterization and/or medications in achieving continence is estimated to reach 70-80% (Liptak, 2004).

When infection occurs, antibiotics are used in combination with the usual techniques of bladder management. In general, high fluid intake is recommended to assist the flow of urine, as residual urine in the bladder fosters bacterial growth and infection.

Intermittent catheterization may not be feasible for, or accepted by, the caregivers of infants and young children. In these cases, a temporary vesicostomy, in which an opening in the bladder is brought out to the level of the skin, may be a useful alternative. Vesicostomies can drain spontaneously and/or be catheterized. Children whose high bladder pressures are refractory to intermittent catheterization and/or medications (approximately 15-30% of patients with myelomeningocele) are candidates for surgical intervention (Liptak, 1998).