Estimation of successful capping with complete aspiration of bladder via nephroureterostomy tube

BACKGROUND Ureteral stent and nephroureterostomy tube(NUT)are treatments of ureteral obstruction.Ureteral stent provides better quality of life.Internalization of NUT is desired whenever possible.AIM To assess outcomes of capping trial among cancer patients with complete aspiration of retained contrast from bladder via NUT.METHODS Our Institutional Review Board approved retrospective review of all NUT placement,NUT exchange and conversion of nephrostomy catheter into NUT performed during June 2013 to June 2015(n=578).Cases were excluded due to lack of imaging of bladder(n=37),incomplete aspiration of bladder(n=324),no attempt at capping NUT(n=166),and patients with confounding factors interfering with results of capping trial including non-compliant bladder,bladder outlet obstruction and catheter malposition(n=14).Study group consisted of 37 procedures in 34 patients(male 19,female 15,age 2-83 years,average 58,median 61)most with cancer(prostate 8,endometrial 5,bladder 4,colorectal 4,breast 2,gastric 2,neuroblastoma 2,cervical 1,ovarian 1,renal 1,sarcoma 1,urothelial 1 and testicular 1)and one with Crohn’s disease.Medical records were reviewed to assess outcomes of capping trial.Exact 95%confidence intervals(95%CI)were calculated.RESULTS Among patients with complete aspiration of retained contrast,30(81%,95%CI:0.65-0.92)catheters were successfully capped(range 12-94 d,average 40,median 24.5)until planned conversion to internal stent(23),routine exchange(5),removal(1)or death unrelated to catheter(1).Seven capping trials(19%,95%CI:0.08-0.35)were unsuccessful(range 2-22 d,average 12,median 10)due to leakage(3),elevated creatinine(2),fever/hematuria(1)and nausea/vomiting(1).CONCLUSION Capping trial success among patients with complete aspiration of retained contrast/urine from bladder via NUT appears high.