Can Extracorporeal Shock Wave Lithotripsy Eradicate Persistent Urinary Infection Associated with Infected Stones?

Abstract

Infected renal stones can be treated by extracorporeal shock wave lithotripsy but it still is not clear whether successful stone fragmentation and the disappearance of all macroscopic stone fragments guarantee eradication of the infection. Therefore, a prospective study was done in 135 patients with renal or upper ureteral stones associated with persistent urinary tract infection. The urinary infection was localized in each patient by bilateral ureteral catheterization. Upper tract infection in the kidney containing the stone was found in 75.6 per cent of the cases. A total of 94 patients completed treatment with extracorporeal shock wave lithotripsy and were followed for 3 to 16 months (mean followup 6.4 months). A marked correlation between the incidence of residual macroscopic stone fragments and the presence of persistent infection was noted. Of the 51 patients who became free of stones 48 (94 per cent) had sterile urine. Only 3 of the 51 patients had persistent infection in the treated kidney despite complete disappearance of the stones. In 45 of the 59 patients with stones smaller than 2cm. (76 per cent) the infection was eradicated, whereas of the 35 with larger stones the urine became sterile in only 13 (37 per cent). We conclude that extracorporeal shock wave lithotripsy can be endorsed for treatment of small infected stones but it is inadequate for treatment of stones larger than 2cm. unless combined with percutaneous nephrolithotripsy or chemical dissolution of the residual infected fragments.