Purpose: Large stone burden can be treated ureteroscopically, but the treatment often requires more than one procedure. Placement of a preoperative stent may theoretically enhance stone clearance by dilating the ureter to facilitate both access and stone removal. This study determines the impact of stent placement before ureteroscopy on operative time, radiologic stone clearance, and reoperative rates.
Materials and methods: We retrospectively reviewed the records of patients who underwent ureteroscopic stone intervention at our institution from 2002 to 2008 by a single surgeon. Nonstented matched controls were used for comparison. Demographics, stone characteristics (size, number, density, and location), presence of preprocedural ureteral stent, operative time, and results of postoperative imaging were compared between the two cohorts. Statistical analysis was performed.
Results: There were 104 patients included in the study (45 prestented and 59 nonstented). Median stone size was 1 cm (range 0.3-4 cm). Overall stone clearance was 95.8%. The median number of procedures was one. Prestenting significantly reduced operative time during first ureteroscopy in patients with large stone requiring multiple ureteroscopies (p = 0.008) and total operative time to stone clearance in patients with stone >1 cm (p = 0.01), but not in patients with stone burdens <1 cm (p = 0.48). Prestenting also significantly reduced reoperative rates in patients with stone burden >1 cm (p = 0.001), especially for stones located in proximal ureter and kidney. Prestenting improves postoperative radiologic clearance, but this was not statistically significant (p = 0.56).
Conclusions: Results show that ureteroscopic lithotripsy of large stone burden can be performed with a high success rate. Preureteroscopic stent placement was associated with a decreased operative time and reoperative rates in patients with larger stone burdens of >1 cm.