Risk Factors for Ureteral Damage in Ureteroscopic stone Treatment: Results of the German Prospective Multicentre Benchmarks of Ureterorenoscopic Stone Treatment-Results in Terms of Complications, Quality of Life, and Stone-Free Rates Project.

Background: The Post-Ureteroscopic Lesion Scale (PULS) is a validated, standardised scale that classifies iatrogenic ureteral lesions during ureteroscopy (URS).

Objective: To determine risk factors for the various PULS-grades caused by URS.

Method: We prospectively investigated the independent influence of various risk factors in correlation with PULS-Grade 1+ and 2+ on 307 patients with ureterorenoscopic stone treatment from 14 German urologic departments.

Results: The following are the outcomes of the study: 117 (38.4%) and 188 (61.6%) of the calculi (median stone size 6 mm) were found in the kidney or ureter; 70% and 82.4% underwent preoperative or postoperative ureteral stenting; 44.3 and 7.2% received laser or ballistic lithotripsy; 60% of the patients presented with PULS grade 1+ and 8% with PULS grade of 2+. Only intracorporal lithotripsy revealed a significant independent risk factor for PULS grade 1+ or 2+. Both laser and ballistic therapies raised the probability of PULS grade 1+ by the factors 3.6 (p < 0.001) and 3.9 (p = 0.021), respectively. The ORs in conjunction with PULS grade 2+ were 3.1 (p = 0.038) and 5.8 (p = 0.014) respectively. Neither endpoint exhibited a significant difference regarding the lithotripsic procedure (laser vs. ballistic).

Conclusion: Intracorporal lithotripsy is associated with a significant increase in damage to the ureter; further research is needed to determine its long-term effects.