The Daily Resistive Index measurement useful tool in the estimation of the optimal time interval between two Shock...

: To monitor the impact of Shock Wave Lithotripsy (SWL) on the renal resisive index (RI) and to investigate the potential of the RI measurement for the estimation of the optimal duration between 2 SWL sessions.

Thirty patients with single pelvis renalis stone were included. Participitants were grouped according to their age as group 1 (<40 years, mean age 36.2+/-3.9 years) and group 2 (>/=40 years, mean age 55.4+/-6.5 years). RI measurement was performed in of all patients prior to SWL. After SWL, RI was monitored daily until RI returned to their pre-SWL values.

The mean stone size was 2 8.97+/-3.62 in group 1 and 10.08+/-4.67 mm in group 2 (p=0.077). Following SWL, the RI value of both goups increased and the higher RI value was measured at the 24th hour as compared with their pre-SWL values (p<0.001). In day 2 RI of the groups declined, but the differences were still statistically different from their pre-SWL RI values (p<0.001). However, on the third day, RI of group 1 was close to their pre-SWL level (p=0.143). But, in group 2, RI value returned to their pre-SWL limits on day 4 (p=0.229).

RI measurement gives important data regarding SWL related acute renal trauma and should be used as an US marker for recovery after SWL.