[Influences of bacteria within stones on ESWL treatment]

On 26 patients with upper urinary stones treated by extracorporeal shock wave lithotripsy (ESWL), the influences of the bacteria within the stones on the inflammatory complications, especially on urinary tract infection, after the ESWL treatment, were studied. The constituents of the stones obtained from these 26 patients consisted of the mixed stone of calcium oxalate and calcium phosphate (10 patients), calcium oxalate alone (2 patients), calcium phosphate alone (1 patient) and uric acid (1 patient). Of these 26 stones including no infection stones such as struvite and carbonate apatite, 5 stones (19.2%) had bacteria within the stone. Although no patients had severe inflammatory complications after ESWL treatments, the fact that the patient group having bacteria within the stones had a significantly elevated body temperature at one day after ESWL treatment compared to that on the preoperative day (P < 0.01) suggests that we should take into consideration the bacteria within non-infection stones as one of the risk factors of inflammatory complications after ESWL treatment.