OUTCOME OF REFLUX IN CHILDREN WITH MYELODYSPLASIA MANAGED BY BLADDER PRESSURE MONITORING

From June 1984 to December 1992 voiding cystourethrography performed on 209 patients with myelodysplasia revealed vesicoureteral reflux in 57 (27%). High grade reflux (3 to 5/5) occurred in 33 patients (58%). Bladder pressure at typical capacity, defined as the pressure at average catheterization volume or bladder leak point pressure, was determined urodynamically. After a mean of 56 months vesicoureteral reflux resolved or improved in 55% of patients and remained unchanged in 28%. There was no correlation between the grade of reflux and the rate of spontaneous resolution. Pressure at typical capacity of 40 cm. water or more was significantly more common in patients with reflux (44%) than in those with no reflux (20%) (p < 0.001). There was a strong association between pressure at typical capacity of 40 cm. water or more and upper tract deterioration (p < 0.0001). However, there was no correlation between pressure at typical capacity and grade of reflux (p = 0.18). Treatment of pressure at typical capacity of 40 cm. water or more led to resolution or improvement of vesicoureteral reflux in 8 of 10 reevaluated patients. Hydronephrosis resolved (7) or improved (1) in 8 of 9 cases. Measurement of intravesical pressure is of paramount importance in the management of spina bifida patients with vesicoureteral reflux. Maintaining the pressure at typical capacity at less than 40 cm. water is associated with increased spontaneous resolution of vesicoureteral reflux and a lower incidence of upper tract deterioration.