Published online Sep 12, 2020. doi: 10.5410/wjcu.v9.i1.1
Peer-review started: April 9, 2020
First decision: June 7, 2020
Revised: July 16, 2020
Accepted: August 15, 2020
Article in press: August 15, 2020
Published online: September 12, 2020
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.
Before internalization of NUT patients should pass a capping trial. Currently there are no indicators of capping trial results.
To help urologists and interventional radiologists estimate successful capping trial during a NUT placement or exchange intervention. By preventing unsuccessful trials, patients and healthcare systems benefit.
578 NUT placement, NUT exchange and conversion of nephrostomy catheter into NUT performed between 2013 and 2015 were reviewed. Exclusions were 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 (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 were calculated.
In 81% of study group (95% confidence intervals: 0.65-0.92) NUTs 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).
The ability to aspirate retained contrast from bladder through NUT is an indicator for successful capping trial. If contrast cannot be aspirated form bladder through NUT, same session tube exchange (upsize or different length) should be considered.
Prospective studies are required to further assess the findings of this study.