Lower urinary tract function after exstrophy closure.

Twenty-eight children with bladder exstrophy, prior to surgery for continence, underwent a urodynamic evaluation, cystogram, ultrasound and dimercaptosuccinic acid scan, to define parameters of lower urinary tract function that are a risk for upper tract damage and/or impair development of bladder capacity. The bladders in 7 of 28 demonstrated no storage function [leak pressure)LP) = 0]; but storage parameters could be measured in the other 21. Their LP was 10-35 cm H2O; 17 of 21 revealed involuntary contractions and 7 of 21 had an end-fill pressure greater than 10 cm H2O. Bladder capacity was better in those with a higher LP and those with no involuntary contractions. The 4 patients with bilateral hydronephrosis (3 of whom also had bilateral multiple scars) were among the 6 with LP greater than 30 cm H2O. Of the 7 with an end-fill pressure greater than 10 cm H2O, 5 had upper tract damage. Involuntary contractions may impair development of capacity. A LP of greater than 30 cm H2O is a risk factor for upper tract damage and an end-fill pressure greater than 10 cm H2O may also be a factor.