Optimal prevention and management of proximal ureteral stent migration and remigration

Purpose: We evaluated issues associated with proximal ureteral stent migration and remigration, including causes and management, and the predictability of ureteral length. Materials and Methods: All proximal ureteral stent migrations that occurred from January 1997 to March 2000 were reviewed. Characteristics and treatment of the 33 patients with proximal ureteral stent migration were compared with those of 66 randomly selected controls who did not have stent migration. We also analyzed a subgroup of 6 cases of remigration. Results: Of the ureteral stents 2% migrated proximally. Mean height was greater in patients with versus without a migrated stent (p = 0.028). The stent-to-ureter length ratio was lower in the migrated than in the nonmigrated group (p <0.0001). Patient height and side of migration were significant predictors of ureteral length (R-2 = 0.3511, p <0.0001 and 0.0007, respectively). Of the patients who required continued ureteral stenting migrated stent management included placement of a longer stent in 9 (group 1) and a stent of equal length in 4 (group 2), and repositioning of the original stent in 4 (group 3). There was no remigration in group 1. However, migration recurred in 2 patients in group 2 (50%) and in all 4 in group 3 (100%). Conclusions: Proximal migration occurs when a stent is too short for the ureter. We recommend that ureteral length should be measured directly from an x-ray to select the optimal stent length. If it is necessary to continue stenting a ureter after migration has been detected, a longer stent should be placed.