Abstract
This study was conducted to determine the impact of stent placement before ureteroscopy on stone clearance.
One-hundred and seventy-one patients（133 nonstented and 38 prestented）underwent ureteroscopic surgery from 2010 to 2012. Median stone sizes were 8 and 9 mm in non- and presented groups, respectively. The 38 patients received stents before stone management because of infection（26 cases）, failure of previous ureteroscopic procedures（10 cases）, and after previous lithotripsy for a prior（i.e., more distal）stone（2 cases）.
Strict stone-free rates with kidney and proximal ureter stones were 40/64（63%）without previous stents and 24/29（83%）with prestenting（P=0.051）. Those of mid or distal ureteral calculi were 66/69（96%）and 9/9（100%）, respectively. Multiple logistic regression analysis revealed that the stone location and prestenting were independent prognostic factors determining stone clearance after ureteroscopy.
Although routine stent placement is not necessary before all ureteroscopic procedures, prestenting was associated with significantly higher stone-free rates, especially with renal and proximal ureteral stones.
