Treatment of Moderate-sized Kidney Stone with Third-generation Electromagnetic Shock Wave Lithotripter

BACKGROUND: The extracorporeal shock wave lithotripsy (ESWL) is a non-invasive method in the treatment of urinary tract stones and its discovery has led to a complete change in the therapeutic strategy for urolithiasis. Due to the low morbidity and excellent fragmentation of the stones, ESWL has proven to be an effective and non-invasive method in the treatment of renal stones. AIM: The aim of this retrospective study is to evaluate the efficacy and safety of the ESWL as a monotherapy in the treatment of moderate size kidney stones with stone area (SA) of 100–300 mm². MATERIALS AND METHODS: We made a retrospective study of 98 patients with moderate size kidney stones with SA of 100–300 mm², divided into two subgroups, into a group with a SA of 100–200 mm² and with 200–300 mm², treated with ESWL in the period of November 2018–December 2019. The patients were treated with a third-generation electromagnetic lithotripter (Lithoskop®, Siemens Medical Systems, Erlangen, Germany), with a source of electromagnetic shocks (Pulso™) and dual ultrasonographic/fluoroscopic system for detection of the stones. The stone location, size, maximum energy used, localization technique, number of shock waves, sessions, re-treatment rate, and additional procedures were reviewed. All the patients before the intervention had a complete laboratory and radiological examinations. Postoperatively, patients were monitored on the 1st, 30th, and 90th post-operative days. RESULTS: Ninety-eight patients with solitary kidney stone with a SA of 100–300 mm² were treated with ESWL. The study included 58 men (59.18%) and 44 women (40.81%). The average length and width of the stone were 15.47 ± 2.68 mm and 12.99 ± 2.83 mm, respectively. The average surface area of the stones in our series was 203.78 ± 72.85 mm². The mean number of treatments for the entire series of patients was 1.82 ± 0.91. The mean number of shock waves for the total series of patients was 3899.11 ± 40. The mean energy used for the overall patient series was 110106.17 ± 21489.61 mJ. The total re-treatment rate was 47.95%. The entire rate of additional procedures was 19.38%. The overall success rate (SR) in our study was 77.55%. The efficiency quotient for the upper-middle and lower calyx was 55.57, 57.15, and 30.81, respectively. CONCLUSION: ESWL is a safe and effective method in the treatment of renal stones, and we recommend as the first method in the treatment of moderate size kidney stone with a surface area of 100–300 mm². The treatment of each patient should be individualized and take into account all favored and non-favored factors that influence the decision to choose extracorporeal lithotripsy as a method of treatment of medium-sized stones.