Stones in enterocystoplasties.

OBJECTIVES

To assess the aetiology of stones which occur in enterocystoplasties and continent diversions, generally attributed to the presence of foreign material, e.g. staples, or to recurrent urinary infection, in patients with augmented or substituted bladders.

PATIENTS AND METHODS

The study comprised 467 patients who had undergone reconstruction of the lower urinary tract and had been followed up for at least 3 years using videourodynamics and ultrasonography.

RESULTS

Stones were found in 42 patients (9%); 50% were found incidentally and the remaining patients presented with symptomatic infections (27%) or deterioration in urinary continence (23%). Stones occurred in 6% of patients with augmentation, in 7% of those with substitution cystoplasty and in 22% of patients with continent diversions. Most patients with stones (88%) used clean intermittent self-catheterization (CISC). Stones were 5-10 times commoner in patients using CISC than in patients voiding spontaneously.

CONCLUSION

Urinary stasis was a more important cause of stone formation than was bacteriuria in patients with cystoplasty. The presence of mucus and bacteriuria are presumed to be contributory. To reduce the risk of stone formation, orthotopic cystoplasty and spontaneous voiding are to be preferred to continent diversion and CISC. Periodic bladder washouts may be an alternative solution.