Japan: Study on Shockwave Lithotripsy for Ureteral Stones

For the treatment of ureteral stones, the outcomes of extremely slow, half-number shockwave lithotripsy are comparable to the standard protocol, a recent study in the journal Urolithiasis has found.

Extracorporeal shock wave lithotripsy is a technique for the treatment of stones in the kidney and ureter that do not need surgery. In the procedure, high-energy shock waves are passed through the body and used for breaking stones into pieces as small as grains of sand. These small pieces can then easily pass from the body with urine.

Toru Kanno, Department of Urology, Ijinkai Takeda General Hospital, Kyoto, Japan, and colleagues conducted the study with the objective to elucidate and compare the safety and efficacy 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 treating ureteral stones.

For this purpose, the researchers conducted a retrospective review between March 2014 and March 2021 of 2410 SWL procedures with reduced or standard protocols (groups R and S) in 1106 patients for ureteral stones.

Treatment success defined as the absence of residual fragments on ultrasonography and plain radiography within 30 and 90 days was the primary outcome. The association between the reduced protocol and treatment success was evaluated using a multivariate logistic regression and propensity score matching analysis. A total of 311 and 544 patients were included in the reduced (R) and standard (S) protocol groups, respectively.

Study Findings

• 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%) and 90 days (88.7% vs. 91.5%).
• The multivariate analysis indicated no significant association between reduced protocol and treatment success within 30 and 90 days.
• Propensity score matching showed no significant difference in the treatment success rates within 30 and 90 days.

The researchers conclude, "the outcomes of extremely slow, half number protocol are comparable to those of the standard protocol for the treatment of ureteral stones."

Reference

Somiya, S., Koterazawa, S., Ito, K. et al. Extremely slow, half-number shockwave lithotripsy for ureteral stones. Urolithiasis (2022). https://doi.org/10.1007/s00240-022-01351-0