Analysis of the Efficacy and Safety of Increasing the Energy Dose Applied Per Session by Increasing the Number of Shock Waves in Extracorporeal Lithotripsy: A Prospective and Comparative Study

摘要

Purpose: To evaluate the efficacy and safety of increasing the energy dose in treating urinary lithiasis with extracorporeal lithotripsy through an expanded number of Shock Waves Per Session (SWPS). Materials and Methods: a randomized, prospective, and comparative study was performed with patients with renal or ureteral lithiasis from 2011 to 2014. Two groups were studied: Group A (n = 136), treated with 3500 SWPS, and Group B (n = 171), subjected to an expanded treatment with 7000 SWPS. Patients were considered stone free when there was no lithiasis or it were less or equal to 4 mm after treatment. Variables related to the patient, stones, treatment, and complications were collected. Results: The global SFR was 75.0% and 87.7% in Groups A and B, respectively (p = 0.004). In renal location, the SFR was higher in Group B (74.1% vs 90.7%, p = 0.003) regardless of the size. In the ureteral location, there were differences in the pelvic only (73.7% vs 95.2%). There were no differences in either the complication rate (27.2% vs 25.7%, p = 0.77), or the severity between the two groups. The variable “number of SWPS” was seen to be an independent predictor of the resolution of lithiasis, having the probability of resolving lithiasis 2.62 (CI 95% = 1.40-4.89) times greater when applying 7000 SWPS. Conclusion: In our study, increasing the energy dose applied through an expanded number of SWPS has been shown to be more effective than standard regimens with a similar safety profile. However, more clinical studies on different types of lithotripters are required to confirm these results.