IntroductionThe 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 methodsThe 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. ResultsThe 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 (r 2 =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). ConclusionsExtracorporeal 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.

Crossed fused renal ectopia (CFRE) is a rare congenital abnormality of the urinary tract where the kidneys are fused on one side, while the ureter of the ectopic kidney crosses the midline with the normal entrance in the bladder on the contralateral side. Congenital anomalies are associated with a stone formation whose management represents a real challenge. To our knowledge, we report the second case of CFRE associated with ureteral stone, which has been successfully resolved with Extracorporeal Shockwave Lithotripsy (ESWL) and the first of its kind where a sufficient degree of stone disintegration has been achieved after a single session with a complete stone clearance during the follow-up. Radiological examination showed an inferior type of CFRE with stone in the proximal part of the ureter of the upper kidney. ESWL is an acceptable and effective treatment option in CFRE patients due to the minimally invasive approach, potentially high stone-free rate, and rare complications.