Comparison of Stone-Free Rates after Ureteroscopic Pneumatic Lithotripsy in Impacted vs. Non-Impacted upper Ureteral Stones

Stone impaction in ureteral is defined as an unchanged stone location for at least 2 months or an inability to pass guidewire up to the stone intraoperatively. This study aims to evaluate the effect of stone impaction on pneumatic transurethral lithotripsy in upper ureteral stones. And to assess if stone impaction could be a factor that prevents retropulsion of upper ureteral stones.

In this retrospective cohort study, patients referred with upper ureteral stone to the urology clinic of Sina hospital between May 2014 to May 2018 were evaluated. The patients were divided into two groups: those with stone impaction (Group A) and those without impaction of stone (Group B). Transurethral lithotripsy (TUL) procedure with pneumatic lithotripter was performed in all patients. The data were extracted from patients’ documents and files retrospectively and analyzed. Quantitate data were shown by the number (%) and they were compared by chi-square test.

70 patients with upper ureteral stones were evaluated. 38 patients (54.2%) in group A and 32 (45.7%) in group B. Average stone size was 7 mm (5-12) and there wasn’t a significant difference in stone burden between the two groups. Stone-free rate (SFR) was significantly less in group B. (90% in group A versus 19% in group B, p-value <0.001). Almost 1.7% of patients experienced complications, there wasn’t a significant difference between the two groups.

Based on the better success rate of pneumatic TUL in upper ureteral impacted stones in comparison with non-impacted stones, we could conclude that having an impacted stone could be a favorable risk factor for successful TUL. The reason could be less migration of these types of stones.