STONE DISEASE

Treatment of large impacted proximal ureteral stones: a prospective randomized comparison of percutaneous antegrade ureterolithotripsy versus retrograde ureterolithotripsy
Sun X, Xia S, Lu J, Liu H, Han B, Li W
The Affiliated First People’s Hospital of Shanghai Jiaotong University, Department of Urology, Shanghai, Shanghai, China
J Endourol. 2008; 22: 913-7

• Purpose: We compared the safety and efficacy of percutaneous antegrade ureterolithotripsy with retrograde ureterolithotripsy for large impacted proximal ureter stones in a prospective randomized manner.
• Materials and Methods: A total of 91 patients with large impacted proximal ureteral stones, defined as stones > 1 cm in size located between the ureteropelvic junction and the lower border of the fourth lumbar vertebra, were prospectively randomized for antegrade (44) or retrograde (47) ureterolithotripsy. Failure of the procedure (conversion to an open procedure), intraoperative and postoperative morbidity, operative time, hospital stay, stone clearance at discharge home, and follow-up were analyzed in each group.
• Results: The main complications were bleeding (2.3%; 1 of 43) for the antegrade procedure and ureteral injury (2.3%; 1 of 44) for the retrograde procedure. Percutaneous antegrade ureterolithotripsy was associated with longer operative times (75.4 ± 11.8 v 30.6 ± 7.8 minutes; P < 0.001), longer hospital stay (6.3 ± 0.5 v 2.1 ± 0.4 days; P < 0.001), and a longer interval to return to normal activities (7.8 ± 0.7 v 2.7 ± 0.6 days; P < 0.001). Nevertheless, the percutaneous antegrade procedure had a higher stone-free rate both at discharge home (95.3% v 79.5%; P = 0.027), and 1 month post-procedure (100% v 86.4%; P = 0.026).
• Conclusions: Percutaneous antegrade ureterolithotripsy is a valuable treatment modality for impacted proximal ureteral calculi larger than 1 cm, and achieves higher stone-free rates than those of retrograde ureteroscopy with holmium:YAG laser lithotripsy. The drawbacks of the antegrade procedure are longer operative time and hospital stay.
  
  
• Editorial Comment
  This study reported higher success with antegrade versus retrograde ureteroscopy for large proximal ureteral stones. The authors should be commended for a well-executed randomized clinical trial that addresses an important question. However, the addition of flexible ureteroscopy to their retrograde approach may have changed the outcome.
  The authors did not utilize flexible ureteroscopy during their retrograde approach - this might impact the stone-free success rate. It would have been helpful to report the size and location of the residual stones - if indeed they were fragments that had migrated to the kidney, these would have been possible to address with the addition of flexible ureteroscopy and stone retrieval. Similarly, flexible ureteroscopy may have facilitated reaching the stone in the 6% of patients who failed the retrograde approach.
  The authors did not utilize flexible nephroscopy for their antegrade approach. This might have allowed the use of a lower pole access, with subsequent lower morbidity (pain, hospital stay, return to normal activities). It would be useful to try to establish predictive factors for failure of the retrograde approach - one might hypothesize that male gender, more proximal location, and high grade obstruction would predispose to either stone migration of difficulty accessing the stone. Lastly, one might consider the use of devices to prevent stone migration, such as the Boston Scientific Stone Cone, Cook N-Trap or PercSys Accordion in the setting of large proximal ureteral stones.

Dr. Manoj Monga
Professor, Department of Urology
University of Minnesota
Edina, Minnesota, USA
E-mail: endourol@yahoo.com