The Efficiency of Extracorporeal Shock Wave Lithotripsy (ESWL) in the Treatment of Distal Ureteral Stones: An Unjustly Forgotten Option?

ABSTRACT

Introduction The optimal management of distal ureteral stones remains a matter of debate since current guidelines favor ureteroscopy over extracorporeal shock wave lithotripsy (ESWL). We aimed to evaluate the efficiency of ESWL for distal ureteral stones and to identify factors that affect treatment outcomes. Materials and methods The retrospective study included records of 115 patients with distal ureteral stones, 5 mm to 18 mm in size, undergoing 223 ESWL sessions as an outpatient procedure. Early fragmentation and three-month follow-up stone-free rate (SFR) was assessed through radiographic imaging. Treatment was successful if there were no residual fragments or they were ≤4 mm, three months after the last session. Results The mean ±standard deviation (range) stone size was 9.68 ±3.10 (5.00-18.0) mm. The mean body mass index (BMI) was 24.3 ±2.67 (18.4-29.8) kg/m² with a significant correlation between BMI and stone size (r2 =0.324, p <0.001). Patients underwent ESWL an average of 1.7 ±1.36 times (1-5), while 68 patients (59.1%) became stone-free after one session. The overall SFR was 82.6%; for patients with stone sizes ≤10 mm and >10 mm, it was 99% and 9.4%, respectively. Cumulative SFR after the second session was 77%. In 20 (17%) patients the treatment was a failure. Complications occurred in 10.4%, while auxiliary procedures were needed in 8.7% of cases, both significantly affected by the stone size (p <0.001). The efficiency quotient (EQ) was 0.76. Treatment outcome was significantly different depending on stone size, BMI, number of sessions, complications, and auxiliary procedures (p <0.001, p =0.022, p <0.001, p <0.001, p <0.001, respectively). Univariate regression analysis identified stone size and BMI as significant predictors of treatment outcome (odds ratio (OR) 3.84, 95% confidence interval (CI) 2.31-8.97, p =0.001, and OR 1.25, 95% CI 1.04-1.54, p =0.024, respectively). Conclusions Extracorporeal shock wave lithotripsy continues to be a safe and effective option for managing simple calculi in distal ureters with a diameter of ≤10 mm. The stone size and BMI remain significant predictors of treatment outcome.