From September 1991 to February 1993, in 83 patients (74 women and nine men, aged 24-86 years), 166 double-J ureteral stents (initially placed to treat fistulas or stenoses located within the inferior third of the ureter) were exchanged during 127 procedures. Stents were extracted from the bladder through the urethra under fluoroscopic monitoring by using a lasso made of a 0.018-inch guide wire and a 7-F catheter. Then a new stent was placed over a 0.035-inch guide wire that had been previously coiled in the renal pelvis. Exchange was successful in 161 (97%) of 165 stents.