Artificial urinary sphincter in the treatment of urinary incontinence: preoperative urodynamics do not predict the need for future bladder augmentation.

PURPOSE: The artificial urinary sphincter has been used to treat urinary incontinence in pediatric patients with neurogenic bladders secondary to myelodysplasia. Frequently bladder augmentation is performed in conjunction with the artificial urinary sphincter implantation. Identifying patients with adequate urinary reservoirs who are candidates for implantation without bladder augmentation is a clinical challenge. We reviewed our experience with the artificial urinary sphincter in children with myelodysplasia to determine whether preoperative urodynamic findings predict the need for future augmentation cystoplasty. MATERIALS AND METHODS: We identified 38 patients younger than 18 years at artificial urinary sphincter implantation who did not undergo augmentation enterocystoplasty before or at implantation. We evaluated preoperative bladder capacity and compliance to determine whether these standard preoperative urodynamic measurements predict the eventual need for bladder augmentation in these patients. RESULTS: In the 15 patients who required eventual bladder augmentation after artificial urinary sphincter implantation mean bladder capacity plus or minus standard deviation was 62.9+/-29.9% of age expected capacity and mean bladder compliance was 8.0+/-4.8 ml./cm. water. In the 23 patients who did not require eventual bladder augmentation mean bladder capacity was 59.2+/-25.4% of age expected capacity and compliance was 7.0+/-3.3 ml./cm. water. There was no statistically significant difference between the 2 groups. CONCLUSIONS: Standard preoperative urodynamics do not predict the patients who undergo isolated artificial urinary sphincter implantation and eventually require bladder augmentation.

Bladder calculi in the pediatric augmented bladder.

PURPOSE: Bladder augmentation is now a commonly accepted treatment in children with neuropathic bladder and other bladder anomalies. Bladder calculi have been reported in a third to a half of pediatric patients after bladder augmentation. We identify the incidence of bladder calculi and risk factors for stone formation in a large series of pediatric patients after bladder augmentation. MATERIALS AND METHODS: We reviewed the records of 286 patients who underwent bladder augmentation between 1978 and 1994, assessed the incidence of and risk factors for bladder calculi, and reviewed treatment methods. RESULTS: Bladder calculi developed in 29 of the 286 patients (10%) who underwent bladder augmentation. The type of bowel used for augmentation did not affect the rate of stone formation except stomach, which did not lead to stone formation in any case. Stones formed more commonly after bladder outlet resistance procedures and in patients with catheterizable abdominal wall stomas. Patients underwent open cystolithotomy or cystolitholapaxy with an overall 44% recurrence rate and no statistically significant difference between treatment methods. CONCLUSIONS: Bladder calculi are a known complication of bladder augmentation. An increased risk of stone formation is associated with bladder outlet resistance procedures and catheterizable abdominal wall stomas. Daily irrigations to clear mucus and crystals as well as complete emptying of the augmented bladder may have important roles in decreasing stone formation.