Yencilek E et al, 2015: The Daily Resistive Index measurement useful tool in the estimation of the optimal time interval between two Shock Wave Lithotripsy sessions.
Yencilek E, Sarsılmaz A, Kilickesmez O, Koyuncu H, Eryildirim B, Gurses B, Bastug Y, Erihan B.
Department of Radiology, Haydarpasa Numune Education and Research Hospital, Istanbul, Turkey.
Department of Radiology, Yeditepe University Medical Faculty, Istanbul, Turkey.
Department of Radiology Istanbul Education Hospital, Istanbul, Turkey.
Department of Urology, Yeditepe University Medical Faculty, Istanbul, Turkey.
Department of Urology Kartal Lutfi Kırdar Education and Research Hospital, Istanbul, Turkey.
Department of Urology Beykoz State Hospital, Istanbul, Turkey.
Abstract
AIMS: To monitor the impact of Shock Wave Lithotripsy (SWL) on the renal resistive index (RI) and to investigate the potential of the RI measurement for the estimation of the optimal duration between 2 SWL sessions.
MATERIAL AND METHODS: Thirty patients with single pelvis renalis stone were included. Participants were grouped according to their age as group 1 (<40 years, mean age 36.2±3.9years) and group 2 (≥40 years, mean age 55.4±6.5years). 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.
RESULTS: The mean stone size was 8.97±3.62 in group 1 and 10.08±4.67mm 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).
CONCLUSIONS: RI measurement gives important data regarding SWL related acute renal trauma and should be used as an US marker for recovery after SWL.
Med Ultrason. 2015 Jun;17(2):175-9. doi: 10.11152/mu.2013.2066.172.dyr.
Comments 1
I like the principle message: there must be ways to measure and determine when a repeat ESWL is safe.
In fact it is difficult to understand that - 35 years after the introduction of ESWL - there is no basis for the decision when a repeat session can be done. The actual EAU urolithiasis guideline offers only a low quality level of evidence 4 information: “There are no conclusive data on the intervals required between repeated SWL sessions. However, clinical experience indicates that repeat sessions are feasible (within 1 day for ureteral stones)”.
Unfortunately the paper has some weakness: Authors from 5 departments collected data from a small patient group. In the material and methods section the authors give the impression as if the age groups were formed before the treatment but in the discussion it says :” We do not have data to explain the underlying reason for the differences in RI recovery between age groups” It seems as if the age groups were formed after the treatment when they worked with statistics on their data. It is nevertheless a good stimulus to go on working on that topic.
May be the report in another publication in this review series could also be used to answer the question when a repeat ESWL is safe: (Hughes SF,et al. A Pilot Study to Evaluate Haemostatic Function, following Shock Wave Lithotripsy (SWL) for the Treatment of Solitary Kidney Stones. PLoS One. 2015 May 4;10(5):e0125840. doi: 10.1371/journal.pone.0125840. eCollection 2015)