Effects of extracorporeal shock-wave lithotripsy on intrarenal resistive index

This prospective study was performed to determine whether extracorporeal shock-wave lithotripsy (ESWL), widely used for treating renal and ureteral stones, affects the kidney interlobar artery resistive index (RI).

A total of 43 patients (30 with renal and 13 with ureteral stones) underwent color Doppler examination before and 30 min and 3 h after ESWL. Seventeen patients with renal and nine with ureteral stones underwent Doppler examination 2 weeks later. Measurements were made near the stones (nearby region), at least 2 cm from the stones (remote region) and in the contralateral kidney for renal stones, and in the ipsilateral and contralateral kidneys for ureteral stones.

In patients with renal stones, the RI was increased 30 min and 3 h after ESWL in the nearby and remote regions, and more markedly in the former. In the contralateral kidney, there was an increase in RI only at 3 h, which was less than that in the ipsilateral kidney. The RI at 2 weeks post-ESWL in the nearby region and contralateral kidney did not differ from the pre-ESWL values. ESWL performed for ureteral stones caused no increase in RI in the ipsilateral kidney.

Patients with renal stones had a temporary increase in RI in the hours following ESWL in both the ipsilateral and contralateral kidneys, which was highest in the region near the stones and lowest in the contralateral kidney. Two weeks later, the RI in both areas had returned to pre-ESWL levels.