Predictive Variables of Success in Extracorporeal Shock Wave Lithotripsy

Kidney stone is a prevalent disease, especially in desert and arid areas like Rafsanjan in Iran. Extracorporeal Shock Wave Lithotripsy (ESWL) is a non-invasive treatment of kidney stones that success rate of which depends on various factors. This study aimed at investigating predictive variables of success in ESWL in patients referred to the ESWL Unit of Moradi hospital (Rafsanjan, Kerman, Iran) in 2016.
All patients referred to the ESWL unit in the hospital during a 6-month period in 2016 were included in this study. Demographic information, size, location, and orientation of stones were collected from interviews and sonography observations. Finally, the obtained data was investigated with the statistical Chi-square and logistic regression tests.
The male to female ratio in patients with kidney stones was almost 2:1, and the overall estimated rate of lithotripsy was 71.7%. There was no difference between the male and female patients in the success of lithotripsy and, in addition, stone location did not affect the rate of success. The only successful predictor of ESWL was stone size. The larger stones were more successful broken than smaller.
Stone size plays an important role in the selection of treatment method. Breaking of larger stones is more successful in ESWL due to the greater absorption of ultrasonic energy emitted by the machine and because of the more accurate determination of their location.