Conference Coverage

Furosemide speeds ureteral patency confirmation, but is time savings worth the risk?



Use of the diuretic furosemide with cystoscopy for confirmation of ureteral patency results in a time savings of 78.5 seconds, according to results from a new randomized, controlled trial.

Dr. Simon Patton of Witchita, Kansas

Dr. Simon Patton

“It does make a difference, but is that really a [meaningful] difference? Every medication has adverse effects, so is it worth that extra time [savings] to take on that potential for side effects? It highlights the importance of statistical significance versus clinical significance, and I think [the clinical significance] can just be answered by each individual physician,” Simon Patton, MD, said in an interview.

Dr. Patton is a urogynecologist at Ascension Via Christi Medical Group in Wichita, Kan. He presented the study, which was conducted during his time as a fellow at the University of South Florida, Tampa, at the annual scientific meeting of the Society of Gynecologic Surgeons. Dr. Patton isn’t sure just how often physicians use furosemide during routine cystoscopy. “It would be great to do a survey to find out how many people use it in their practice,” he said.

Cystoscopy is used to during a surgery to ensure that no injury has been done to the bladder or the urethra, and the American Urogynecological Society recommends that it be performed during any pelvic reconstructive surgery. A key element of the test is confirming that the ureters are open. By increasing urine flow, furosemide can reduce the time to confirmation. But after conferring with a colleague who used the procedure, Dr. Patton looked for some data to support the practice and couldn’t find any.

Although the cystoscopy itself generally is safe, furosemide can cause hypotension, change in renal function, and even dehydration at higher doses. During the question-and-answer period, one attendee noted these issues and pointed out that furosemide can potentiate renal failure, especially among patients taking cephalosporins. “If you’re going to do this sort of trial, you have to consider potential adverse events. A single dose is probably not going to [cause an issue], but in the context of a study you want to monitor the adverse events that have been reported,” this attendee said.

The researchers did not observe any of these adverse events during the study, but Dr. Patton noted that the study was not powered to detect them. “We felt that with the low-dose, single-time [exposure], it was appropriate to not worry too much about those side effects,” he replied.

Another potential concern is that the increased urine flow could mask a kink in the ureter by forcing it open.

In the study, his team randomized 145 patients with a planned cystoscopy as part of a procedure to receive 10-mg furosemide (1 cc) or saline (1 cc) during a cystoscopy performed by an attending or a fellow. The median time to confirmation of ureteral patency was 86.5 seconds in the furosemide group, compared with 165.0 seconds in the saline group (difference, 78.5 seconds; P less than .001). The time to the first ureteral jet was 59 seconds versus 74 seconds, respectively (P less than .006). A Kaplan-Meier survival curve analysis also showed a significant improvement in time to ureteral patency confirmation (log-rank P less than .001).

The study was not funded. Dr. Patton has no relevant financial disclosures.

SOURCE: Patton S et al. SGS 2019, Abstract 10.

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