Background: The lower third is the location of the great majority of ureteral stones. Treatment of these stones remains controversial: in situ extracorporeal shockwave lithotripsy (SWL) vs. ureteroscopy (URS).
Methods: During the last decade, 633 distal ureteral calculi were treated at our institution using in situ SWL (Siemens Lithostar electromagnetic lithotripter) in 395 patients and URS (with 11.5F instrument and ultrasonic lithotripsy) in 228 patients. The patients' age and stone size were similar in the two groups. All SWL therapies were performed on an outpatient basis.
Results: The overall success rate was 99% for SWL, and the efficiency quotient (EQ) was 92.4%. The treatment was more effective for <10 mm calculi. In the URS group, there was a 92% overall success rate with an EQ at 91.2%. Compared with SWL, URS was more time consuming, at least for the initial cases; often required intravenous sedation; entailed routine placement of a ureteral stent; and more often led to hospitalization. On the other hand, stone clearance was rapid after URS, although most of the SWL patients were stone free at the end of 6 weeks. The cost was similar in the two groups.
Conclusion: We believe that multiple factors should be considered when deciding the most appropriate approach to distal ureteral calculi. In situ SWL provides optimal first-line treatment for calculi < 10 mm, whereas URS is better reserved for stones >10 mm.