Efficacy and safety of extracorporeal shock wave lithotripsy in the 21th century - controversy and clinical practice
Abstract
Objective: Evaluation of extracorporeal shock wave lithotripsy efficacy and safety in a prospectively followed group of patients treated by this procedure. Determination of the factors that may affect efficacy of the procedure and analysis of the possible risk factors for the development of renal parenchymal damage due to the use of shock wave.
Methods: We assessed 301 extracorporeal shock wave lithotripsy procedures performed in 250 patients from December 2012 to October 2015. All procedures were performed under analgosedation with the use of the electromagnetic source EMSE 140f machine Dornier Compact Sigma on the basis of the standardized protocol which was determined before the study.
This protocol took into account the size and the localization of the stones. Efficacy quotient (EQ) and stone free rate (SFR) were used in order to evaluate the procedure effectiveness.
The relationship between the procedure efficacy and body mass index (BMI), the lithiasis size and the location and the overall energy dose applied (Edose) was analysed. For the purpose of the procedure safety evaluation ultrasound examination aiming at the presence of subcapsular or perirenal haematoma were performed after each procedure.
Positive findings were subsequently verified by spiral CT examination. We tried to analyse the possible risk factors for the development of renal parenchymal injury after the use of shock waves.
Results: Ultrasound, native nephrogram or CT was performed three months after the procedure to assess the treatment results. SFR and EQ were achieved in 78.6 % and 56.6 % of our patients respectively.
Development of the renal hematoma was detected in 11 patients (4.5 %), from this group three patients had symptomatic hematoma (1.23 %). The patients with ureterolithiasis were excluded from the procedure safety evaluation as the shock wave trajectory in these patients makes the risk of renal injury quite improbable.
BMI and Edose proved to have influence on the efficacy and safety of the procedure in our study. The same applies for previous renal infection and urinary tract stenting.
Conclusion: We demonstrated good efficacy of ESWL (extracorporeal shock wave lithotripsy) and at the same time we confirmed the assumption that the incidence of kidney damage is higher than it was supposed in the past. The overall energy dose applied is essential for the efficacy and safety of the procedure.
Due to the absence of any general guidelines we consider important that every department monitors their own results and to optimize the energy dose for every particular lithotriptor. We further recommend introduction of an efficacy safety quotient (ESQ) and close monitoring of the factors influencing the efficacy and safety of the procedure.
Therapeutic approach towards the peripheral lithiasis and lower pole calyx peripheral lithiasis in particular remains challenging and problematic.