Proximal ureteral stent migration: an avoidable complication?

The parameters responsible for proximal ureteral stent migration were quantitated. We compared 16 patients seen between 1990 and 1993 with stent migration to 32 patients whose stents did not migrate. The stent indwelling time and number of stents with a proximal curl of less than 180 degrees were similar between the groups. More patients with migration had stents that were shorter than the ideal length, with a distal curl of less than 180 degrees and a proximal curl in the upper calix versus the renal pelvis. A shorter than ideal stent, inadequate distal curl and a proximal curl in the upper calix appear to be significant factors in the process of stent migration.