Holmium:YAG Laser Lithotripsy as a Treatment Modality for Ureteral Calculi

Purpose: We evaluated the results of Holmium:YAG laser lithotripsy according to the size and location of the ureteral stones. Materials and Methods: Between March 1998 and April 2007, the medical records of 203 patients who were treated with ureteroscopic Holmium: YAG laser lithotripsy due to ureteral calculi were reviewed. They were subgrouped by the size and the location of the ureteral stones. The results of treatment were evaluated by the stone free rate and the mean operation time of each group. Results: The stone free rates of the upper, mid and lower ureter stone groups were 73.3%, 96.1% and 100%, respectively. There was a significant difference in the upper ureter stone group compared to the other two groups, and especially for the group with stone less than 10mm. Stone migration into the renal pelvis or calyx was a major cause of failure in the patients with upper ureter stones. 8 cases showed stone migration and 2 cases showed fragment migration. Conclusions: As Holmium:YAG laser lithotripsy has a low complication rate and a high stone free rate, it is an effective treatment modality for ureteral calculi. However, such procedures should be performed carefully because the thermal effect of the Holmium:YAG laser causes ureteral perforation, and especially in the cases of impacted or large stones. Other effective alternatives such as trapping devices need to be studied for patients with upper ureteral stones to prevent stone migration. (Korean J Urol 2008;49:60-65) 󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏