Preservation of renal function in children with myelomeningocele managed with basic newborn evaluation and close followup.

Abstract

Children with myelomeningocele who leak with high intravesical pressures are at risk for upper urinary tract deterioration. Urodynamic study shortly after birth and routinely thereafter has been advocated to predict which newborns are at risk for upper tract deterioration. We hypothesize an approach that excludes routine application of urodynamic evaluation in neonates, reserving this study for use only when clinically indicated, is a safe and effective management option. Of 188 patients seen in the myelomeningocele clinic 84 underwent initial evaluation at age 6 months or less and comprise the study group. Initial evaluation consisted of a history, physical examination, urine culture and renal ultrasound. Infants with hydronephrosis or evidence of retention were placed into a high risk group and all others were placed into a low risk group. High risk patients underwent prompt urodynamic evaluation. High and low risk patients were followed closely at 2 to 4-month intervals with serial physical examination, upper tract imaging and urine culture. Conversion from low to high risk occurred with new onset hydronephrosis, febrile urinary tract infection, urinary retention or incidental finding of vesicoureteral reflux at the time of evaluation for continence. These findings warranted urodynamic evaluation and appropriate intervention. Upper tract deterioration, defined as new onset hydronephrosis, was distinguished from renal deterioration, defined as cortical thinning or scarring, failure of renal growth or decreased renal function on renal scan. A total of 18 infants were placed into the high risk group at initial evaluation, including 12 for retention and 6 for hydronephrosis. The majority of patients were treated with clean intermittent catheterization or vesicostomy. Of the 65 infants placed into the low risk group 29 were converted to high risk at a mean age of 3.1 years, most commonly for febrile urinary tract infection (45%), and appropriate intervention was instituted. Mean followup is 10.4 years (range 0.25 to 26.5). Despite the occurrence of upper tract deterioration, renal deterioration occurred in only 2 of the 162 total renal units (1.2%). Basic evaluation of the newborn with myelomeningocele along with careful followup and intervention when indicated results in an excellent rate of renal preservation and represents a safe method of management.