Extremely-slow, half-number shockwave lithotripsy for ureteral stones

Abstract Purpose To elucidate and compare the treatment success rate and safety of the reduced (30 shocks/min with 1,200 shocks/session) and standard protocols (60 shocks/min with 2,400 shocks/session) of extracorporeal shockwave lithotripsy (SWL) for ureteral stones treatment. Materials and Methods 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 patients chose either group after hearing an explanation of both protocols. 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. Results 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. There was no significant difference 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 overall complication rates did not differ significantly between the groups (p = 0.45). 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 or overall complication rates. Conclusion The Extremely slow, half number protocol outcomes are comparable to those of the standard protocol for treating ureteral stones.