Bladder calculi in children who perform clean intermittent catheterization.

OBJECTIVE

To examine the role of clean intermittent catheterization (CIC) as a possible predisposing risk factor for bladder calculi, assessing risk factors in patients with and without bladder augmentation, and to evaluate management options for bladder calculi in these patients.

PATIENTS AND METHODS

The records of 403 patients who were using a regimen of CIC between January 1981 and March 1998 were reviewed to identify those forming bladder calculi; stones were diagnosed in 28 patients. The patients were categorized as: group 1, patients with no bladder augmentation who catheterized urethrally (227, group 1a) or via a Mitrofanoff conduit (18, group 1b); group 2, patients with augmented bladders who catheterized urethrally (100, group 2a) or via a Mitrofanoff conduit (58, group 2b). The incidence of bladder calculi in each group was determined and compared statistically where applicable. The success of the treatment options for stone management was reviewed.

RESULTS

Bladder calculi developed in 5% of patients in group 1a, 8% in group 2a, 11% in group 1b, and 10% in group 2b; the incidence of calculi was not significantly different among the groups. Of these patients, 18 (64%) were asymptomatic at the time of diagnosis and significant bacteriuria was found in 23 (88%). Difficulty in catheterizing either the Mitrofanoff conduit or the native urethra was reported in 14 (50%) of these patients. Calculi were more often solitary (71%) and typically composed of struvite or apatite. Calculi were managed by open cystolithotomy in 15 patients (54%) and endoscopically in 13 (46%). Stones recurred in nine patients (32%) after treatment, comprising four of six patients treated endoscopically with electrohydraulic lithotripsy and in five of 15 after open cystolithotomy. The mean interval to recurrence was 22.8 months.

CONCLUSION

These results suggest that patients on a regimen of CIC are at risk of developing bladder calculi but the incidence of calculi is not influenced by bladder augmentation. The presence of a Mitrofanoff conduit was associated with a slightly increased incidence of calculus formation. Open cystolithotomy was associated with a lower stone recurrence rate but there were too few patients to draw definitive conclusions.