Phenazopyridine for Evaluation of Ureteral Patency: A Randomized Controlled Trial.

Objective: To evaluate the usefulness of phenazopyridine for confirmation of ureteral patency during intraoperative cystoscopy.

Methods: We conducted a randomized controlled trial comparing use of phenazopyridine with no medications for evaluation of ureteral patency during intraoperative cystoscopy in women undergoing pelvic surgery. The primary study outcome was time to visualize ureteral urine efflux. To detect a 3-minute difference with α of 0.05 using a two-sided, two-sample t test and β 0.80 required 98 patients equally divided into two groups.

Results: A total of 104 women were randomized from April to December 2015. Patients in the treatment group tended to be older (P=.02); otherwise, study groups were similar. Time to visualize ureteral urine efflux did not differ between study groups with a mean time of 2 minutes 40 seconds (±2 minutes 38 seconds) in the control group and 2 minutes 53 seconds (±4 minutes 35 seconds) in the treatment group (P=.77). Regarding the surgeon survey, surgeons felt less frustrated and impatient in visualization of ureteral urine efflux in the treatment group compared with the control group (mean response 1.5±0.8 in treatment compared with 2.0±1.0 in control, P=.007), and surgeons felt that the cystoscopy took too long more often in the control than in the treatment group (1.7±0.9 in treatment compared with 2.1±1.0 in control, P=.02). Trial of void result differed significantly between groups with fewer patients in the treatment group failing a void trial (P=.04). There were no adverse events related to phenazopyridine use.

Conclusion: Preoperative phenazopyridine is a useful and cost-saving medication for use in planned cystoscopy for evaluation of ureteral patency.

Clinical Trial Registration: ClinicalTrials.gov, https://clinicaltrials.gov/, NCT02424149.