Is ureteral stent an effective way to deliver drugs such as bacillus Calmette-Guérin to the upper urinary tract? An experimental study

BACKGROUND: We aim to evaluate the distribution in the upper urinary tract of intravesical-delivered fluids, after inducing vesicoureteral reflux (VUR) with a double J stent. METHODS: In group 1 (n = 35) patients were maintained in a 20° Trendelenburg position and were evaluated after immediate insertion of ureteral stent, while in group 2 (n = 16) patients were evaluated after several days with ureteral stent placement. Patients in both groups were submitted to a cystogram with progressive volumes of iodine contrast and were evaluated according to VUR of contrast medium to the renal pelvis. Additionally, in group 2 visual confirmation was performed by endoscopic inspection of upper tract mucosal impregnation with methylene blue. RESULTS: In group 1, after immediate insertion of ureteral stent reflux occurred in 51.4% (n = 18/35), and after several days with ureteral stent placement reflux was observed in 87.5% (n = 14/16) of patients. Reflux was progressively more frequent according to increasing bladder volume (p < 0.001). At 60 ml bladder volume no reflux was observed, while at 120 ml, 180 ml, 240 ml, 300 ml and 360 ml bladder volume reflux was observed in 14%, 25%, 41%, 55% and 63% of patients, respectively. CONCLUSION: Retrograde delivery of fluids such as bacillus Calmette-Guérin to the upper urinary tract through double J stents can be effective; however, it is mainly effective after several days with ureteral stent and relatively large volumes might be instilled into the bladder.