Polyacrylamide Bulking Curbs Vesicoureteral Reflux in Kids

April 26, 2013

By David Douglas

NEW YORK (Reuters Health) Apr 26 - For vesicoureteral reflux (VUR) in children, endoscopic injection of polyacrylamide hydrogel may be a less expensive alternative to dextranomer hyaluronic acid, Canadian researchers suggest.

In a population with primarily low-grade VUR, technique and short-term success rates were comparable with the polyacrylamide hydrogel product Bulkamid (Contura) and the most popular bulking agent, dextranomer hyaluronic acid (Dx/HA, Deflux, Q-Med), Dr. Stéphane Bolduc told Reuters Health by email.

"Moreover, there is a lower cost per treatment (at our institution, in Canada) and there were no significant complications," Dr. Bolduc said.

In a March 26th online paper in the Journal of Urology, Dr. Bolduc of Centre Hospitalier Universitaire de Québec and colleagues observe that endoscopic management is now considered a first line treatment option for all grades of reflux at most centers.

Dx/HA is FDA approved, but its overall success rate is only 77% and it's relatively costly, the researchers say. They believed polyacrylamide hydrogel (PAHG) might be a good off label alternative, because it's approved for periurethral injection in urinary stress incontinence and maintains its volume after injection.

In a prospective study, the researchers used PAHG injection in 40 patients with IRS grades ranging from I to V. Twenty-nine patients had bilateral flux, so a total of 69 ureters were treated. The median age was 50 months, and the mean volume injected was 1.1 mL.

At three months, the success rate in grades I-III VUR was 84.7% after a single treatment and 87.0% after two injections. The overall success rate for all grades using up two injections was 81.2%.

Not only was the study not a randomized trial, but as the authors themselves point out, it involved a relatively small group of patients and only three months of follow-up.

Given the findings, Dr. Bolduc said, trials comparing PAHG to Dx/HA would be worthwhile.

At his institution, he said, the price per 1 mL vial of Bulkamid is about $700 CAD (about US$737) and for Deflux about $850 CAD (about US$836). As mentioned, a mean of 1.1 mL was used during the procedure. A second vial had to be opened to deal with 26 of the 69 refluxing ureters.

As for the FDA status of Bulkamid in this setting, Dr. Bolduc said, "the company might look into it -- to open multicenter studies and get approval."

"There is a study recruiting patients for adult female stress urinary incontinence," he added, "but we are the only study around the globe for reflux. I am personally looking at initiating an investigator-initiated study (not supported by the company) with other Canadian centers."

SOURCE: https://bit.ly/11nxxTF

J Urol 2013.