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 augumented bladder may have important roles in decreasing stone formation.