Bladder stones after bladder augmentation are not what they seem

In patients with bladder augmentation, 1/3 of bladder stones and >1/2 of renal stones were non-infectious. Furthermore, an infectious stone does not imply an infectious recurrent stone and no known clinical variables appear to be associated with stone composition, suggesting that there is a possible metabolic component in stone formation after bladder augmentation.Table. Stone composition of bladder and renal stones in patients with augmented bladders.Stone compositionBladder stones (n = 143) (%)Renal stones (n = 30) (%)Infectious stones99 (69.2%)12 (40.0%) Struvite79 (55.2%)11 (36.7%) Pure carbonate apatite15 (10.5%)1 (3.3%) Pure ammonium acid ureate2 (1.4%)0 (0.0%) Mixed stones with calcium phosphate4 (2.8%)0 (0.0%)Non-infectious stones44 (30.8%)18 (60.0%) Calcium phosphate41 (28.7%)14 (46.7%) Pure calcium oxalate0 (0.0%)4 (13.3%) Uric acid3 (2.1%)0 (0.0%)