Comparison of an electromagnetic and an electrohydraulic lithotripter: Efficacy, pain and complications

We analyzed efficacy and complications of extracorporeal shock wave lithotripsy (SWL) and analgesia requirement during the treatment in two groups of patients treated with different lithotripters.

The patients treated were 189, 102 between September 2016 and April 2017 with HMT Lithotron® LITS 172, electrohydraulic, and 87 between May and September 2017 with Storz Medical Modulith® SLK, electromagnetic. The main differences between the lithotripters are: type of energy source, patient position, frequency and number of shock waves. All the patients underwent sonography before and four to eight weeks after the treatment. The targeting was sonographic for renal stones and X-ray for ureteral stones. All the patients received Ketorolac before the treatment with a supplement of Pethidine if needed. People lost to follow-up and with incomplete data were excluded.

We enrolled 173 patients, 94 treated with the electrohydraulic lithotripter and 79 with the electromagnetic one. 43 patients (54%) in the electromagnetic group and 31 (33%) in the electrohydraulic group were stone free or presented clinically insignificant residual fragments (CIRFs), defined as asymptomatic, noninfectious, ≤ 3 mm. The association between CIRFs and the kind of lithotripter was statistically significant (p = 0.004). An increased need for analgesia was found in 14.9% of patients in the electromagnetic group and in 81% of patients in the electrohydraulic group (p < 0.001). The access to emergency room (intractable pain, kidney failure, fever, Steintrasse) after the treatment was similar in the two groups (p = 0.37).

The best results in stones fragmentation and less analgesia requirement were demonstrated in the electromagnetic lithotripter group. No differences were demonstrated considering the need for emergency room after the treatment.