Somiya S. et al., 2023: Extremely slow, half-number shockwave lithotripsy for ureteral stones
Somiya S, Koterazawa S, Ito K, Haitani T, Yamada H, Kanno T.
Department of Urology, Ijinkai Takeda General Hospital, 28-1 Ishida Moriminami-cho, Fushimi-ku, Kyoto, 601-1495, Japan.
Department of Urology, Ijinkai Takeda General Hospital, 28-1 Ishida Moriminami-cho, Fushimi-ku, Kyoto, 601-1495, Japan.
Abstract
To elucidate and compare the efficacy and safety of the reduced (30 shocks/min with 1200 shocks/session) and standard protocols (60 shocks/min with 2400 shocks/session) of extracorporeal shockwave lithotripsy (SWL) for ureteral stones treatment. This study was a retrospective review of 2410 SWL procedures with reduced or standard protocols (groups R and S) in 1106 patients for ureteral stones between March 2014 and March 2021. The primary outcome was treatment success, defined as the absence of residual fragments on ultrasonography and plain radiography within 30 and 90 days. A multivariate logistic regression and propensity score matching analysis evaluated the association between the reduced protocol and treatment success. This study included 311 and 544 patients in the reduced (R) and standard (S) protocol groups, respectively. The patient's characteristics were comparable, excluding the lithotripter machine. No significant difference was observed between groups R and S in treatment success rates within 30 (63.3 vs. 65.8%, p = 0.50) and 90 days (88.7 vs. 91.5%, p = 0.18). The multivariate analysis indicated no significant association between reduced protocol and treatment success within 30 and 90 days (p = 0.44 and p = 0.68, respectively). Propensity score matching showed no significant difference in the treatment success rates within 30 and 90 days. The Extremely slow, half number protocol outcomes are comparable to those of the standard protocol for treating ureteral stones.
Urolithiasis. 2022 Oct;50(5):635-641. doi: 10.1007/s00240-022-01351-0. Epub 2022 Aug 15.PMID: 35969268
Comments 1
The group has published a similar study on renal stones with comparable good outcomes (1). It is assumed that appr. 40% of shocks do not hit the target because of kidney movement of 12-18 / minute during respiration. However, respiration triggering has been given up years ago and shooting during deep inspiration is probably not done any more. None of this applies to ureteral stones either, which hardly move when you breathe.
So, the only explanation is the time needed for the disappearance of the cavitation bubbles.
1 Ito K, et al. Extremely-slow, half-number shockwave lithotripsy for asymptomatic renal stones