The risk factors of ureteral stricture after treatment for ureteral calculi

Abstract

Purpose: After treatment of ureteral calculi, some patients will develop ureteral stricture at the identical site of the calculi. Therefore, we have retrospectively evaluated the records of patients who had been treated for ureteral calculi to determine the risk factors that lead to the development of ureteral stricture. Materials and methods: Between January 1995 and July 2004, 2,083 patients visited Chung-Ang University Hospital for treatment of ureteral calculi. They underwent extracorporeal shock wave lithotripsy (ESWL, 2,263 patients), ureteroscopic lithotripsy (URSL, 219 patients), laparoscopic ureterolithotomy or open ureterolithotomy (321 patients). Among these patients, 18 developed ureteral stricture at the identical site of the calculus, and they were managed by ureteroplasty or balloon dilatation. To define the risk factors of ureteral stricture, we examined the stone size, impaction of stone, the degree of hydronephrosis and the method of calculi treatment. Results: The ureterolithotomy or laparoscopic ureterolithotomy (1.25%) that required ureterotomy was most common cause of ureteral stricture. The secondary common cause of the ureteral stricture was URSL (0.91%) and the third was ESWL (0.53%). The degree of hydronephrosis didn't affect the formation of ureteral stricture (p>0.05). The stones larger than 1cm developed more frequent ureteral stricture than the stones smaller than 1cm (>1cm: 0.31%, ≤1cm: 1.39%, p=0.0022). The impacted stone developed more frequent ureteral stricture than the non-impacted stone (impacted stone 1.28%, non-impacted stone 0.13%, p=0.0004). Conclusions: Ureterolithotomy and laparoscopic ureterolithotomy led to the development of more frequent ureteral stricture than did URSL or ESWL. Therefore, ureterotomy was the main risk factor for developing ureteral stricture after the treatment of ureteral calculi. The stone larger than 1cm in diameter and the impacted stone were confirmed as the main risk factors of ureteral stricture after the treatment for ureteral calculi.