Development of the urodynamic pattern in infants with myelomeningocele

Abstract

Objective: To study changes in the urodynamic pattern during the first year of life in patients with myelomeningocele (MMC) and to correlate these to deleterious effects on the upper urinary tract.

Patients: methods Thirty-four infants with MMC were investigated using cystometry, micturating cystourethrography and urography at 1, 4 and 10 months of age.

Results: Detrusor contractility was characterized by an increase in activity, with hyper-reflexia in 45% initially, increasing to 65% at the 4-month investigation. During the same period, the number of infants with areflexia decreased from 25% to 12%. Between 4 and 10 months, there were only minor changes in detrusor contractility. The number of patients with poorly compliant bladders also increased between the first and fourth month. The number of patients with elevated outlet resistance increased only slightly during the first year, from 32% of all infants at the initial investigation to 40% at the 10-month follow-up. Vesico-ureteric reflux was detected in 12 of the patients during the year, with five already diagnosed at the first investigation. Almost all refluxes were cured with clean intermittent catheterization, with additional pharmacological therapy in two patients; one patient required a vesicostomy.

Conclusions: This study indicates that detrusor activity, and to some extent outlet resistance, change during the first year of life in infants with MMC. The changes were mainly increases in activity and occurred mostly between the first and fourth months of age. There was a strong correlation between the occurrence of reflux and poor compliance, hypercontractility and outlet obstruction.