Abstract
Background and Objectives: Extracorporeal shock wave lithotripsy (ESWL) has replaced most surgical and endourologic froms of therapy for urinary tract stone disease.
Despite its proved safety and efficacy, its adverse effects on renal function are still to be identified. A newer diagnostic technique, color Doppler utltrasonography, has brought a new insight into renal function. It enables precise evaluation of the renal vascular supply. Change in intrarenal vascular resistance after ESWL were studied with Doppler ultrasound techniques.
Material and Methods: In 55 consecutive patients the resistive index (R1) was measured at an interlobar artry before and 30 min after ESWL in the treated kidney. In 22 patients follow-up Doppler study performed 1 week after ESWL.
Results: In the treated kidney, RI significantly increased from 0.62 ±0.05 (mean±SD) on baseline to 0.66 ± 0.06 (p= 0.0001). There was no significant correlation of increase in RI with patient age. A follow-up doppler study showed that the mean RI didn't return to pretreatment level after 1 week and elderly patients (> or=60 year old, n=3) had higher RI levels (0.76 ± 0.05) on baseline than younger patients (<60 years old, n=19) (0.64±0.06). No correlation was found between ESWL voltage or number of shock waves and changes in RI before and after ESWL.
Conclusion: Because of increasing RI levels on baseline, patients have a risk of post –ESWL renal tissue damage. The measurement of change in RI with Doppler ultrasound techniques after ESWL may provide useful information for clinical diagnosis of renal tissue damage.