To compare the safety and efficacy of two different ureteral occlusion devices (stone cone and entrapment net) in preventing retrograde stone migration during ureteroscopic pneumatic lithotripsy. Proximal migration of stone fragments during ureteroscopic lithotripsy is a common problem, especially when the pneumatic lithotripter is used for stone fragmentation.

A total of 195 patients with proximal ureteric stones were prospectively randomized into one of three groups in this study, with 65 patients in each group. In group I, the Stone Cone was used as a ureteral occlusive device; in group II, the N-Trap was used; and in group III (control group), the patients underwent pneumatic lithotripsy without any ureteral occlusive device.

The ureteroscopic procedure was completed successfully in 180 patients; 63 patients in group I, 59 patients in group II, and 58 patients in group III. Patients in group I showed significantly lower incidence of stone migration compared with the other 2 groups (P <.05). Both ureteral occlusive devices significantly lowered the incidence of residual fragments (>3 mm), ureteral trauma, operative time, and the need for ureteral stenting compared with control group. The stone-free rate at 3 weeks was 95.24%, 83.05%, and 72.41% in groups I, II, and III, respectively. The patients in group I had a statistically significant stone-free rate compared with the other two groups (P <.05). Auxiliary procedures were required in 3 (4.76%), 10 (16.94%), and 16 cases (27.58%) in groups I, II, and III, respectively.

The use of Stone Cone or N-Trap is valuable during ureteroscopic pneumatic lithotripsy for treatment of proximal ureteral stones. Both devices significantly diminish residual fragments, the incidence of ureteral wall trauma, and the need for the auxiliary procedure. However, the stone cone was more effective in preventing proximal stone migration and the subsequent stone-free rate.