Renal changes from extracorporeal shock-wave lithotripsy: evaluation using Doppler sonography

In this study, duplex Doppler sonography was used to evaluate flow changes within renal intraparenchymal vessels induced by extracorporeal shock-wave lithotripsy (ESWL). We have examined 20 patients with caliceal stones before, 1 h and 24 h after ESWL. Doppler waveforms were obtained both from arteries located near the stone and at least at 3 cm from it, and resistive index (RI) measured. A statistically significant increase of the RI (0.079 ▒ 0.039 mean increase; P < 0.001) was detected 1 h after ESWL in vessels located near the stone. After 24 h, RI tended to normalize (0.056 ▒ 0.037 mean decrease; P < 0.001). The residual difference (0.022 ▒ 0.043; P = 0.399) between mean RI values obtained near the stone before and 24 h after ESWL was mainly due to persistent elevated RI values in three patients with ESWL induced hydronephrosis. No significant RI changes were recognized in intraparenchymal vessels located far from the stone. In all patients, Doppler alterations were not associated with morphologic changes of renal parenchyma.