Factors influencing the outcome of extracorporeal shock wave lithotripsy for renal stones and ureteral stones: one hospital experience
Yu-Ting Liou1, Chung-Cheng Wang1,2, Chien-Chih Chen2, Chien-Hua Chen2, Chih-Chun Ke2,
Po-Cheng Chen2, Jui-Hsiang Hsieh1
Department of Biomedical Engineering,Chung Yuan Christian University1
Urology Department,En Chu Kong Hospital2
Extracorporeal shock wave lithotripsy (ESWL) is a widespread method to manage both renal stones and ureteral stones. We investigated the patients who received ESWL in our hospital to find out which factors influenced the outcome.
Materials and Methods:
From January, 2014 to June, 2014, we retrospectively reviewed the chart of 437 patients who underwent ESWL in our hospital. These patients were divided to renal stone group and ureteral stone group. We analyzed the patient character (such as age, sex, height, weight, BMI, and serum creatinine level) and the stone character (stone size, position, the hydronephrosis status detected by renal ultrasound, the pre-operative ureter stent placement) Success for stone-free was defined as <0.4 mm in follow up KUB plain film.
The success rates were 49.6% and 60% in renal stone group and ureteral stone group. In univariate analysis of the renal stone group, we can find that only stone size, the pre-operative hydronephrosis status and the renal stone location showed statistically significant to influence the success rate. In the multivariate logistic regression of the renal stone group, stone width is the independent factor which affects the success rate. In univariate analysis of the ureteral stone group, only the stone size showed statistically significant. In the multivariate logistic regression of the stone length and stone width of the ureteral stone, only stone length is the independent factor.
Stone size is the most important factors influencing the outcome of ESWL both in renal stone and ureteral stone. In renal stone group, the stone width is the major character to affect post-ESWL stone free rate and in the ureteral stone group, the stone length is the major character.