The use of amniotic membrane injection as an adjunct in endoscopic urethral stricture management

Endoscopic urethral stricture treatment has high recurrence rates. Due to research supporting amniotic membrane's (AMs) anti-inflammatory and anti-fibrotic properties reducing scar tissue formation, AM has generated interest in reconstructive urethral surgery. To the best of our knowledge, we performed the first investigation of the success rate of urethral dilation when combined with micronized AM injection for the treatment of urethral stricture.

Eligible patients were adult males with anterior strictures meeting strict criteria for diameter, length, International Prostate Symptom Score (IPSS), and flow rate. Micronized AM was injected in the stricture region during urethral dilation. The primary study endpoint was an anatomical success (≥14Fr) at 6 months. Secondary endpoints were evaluated with the IPSS, urethral stricture surgery - patient-related outcome measure, International Index of Erectile Function, flow rate, and postvoid residual. Outcomes were assessed at baseline and multiple points postinjection. Injection safety was analyzed.

Ten men with a mean age of 52 years were included in the study. At 6 months, 7 of 10 patients demonstrated recurrence of the urethral stricture on cystoscopy. Improvements in secondary endpoints were noted in 10 of 10 patients at 3 months and 3 of 10 patients at 6 months. No adverse events were observed.

To the best of our knowledge, this is the first study evaluating micronized AM injection as an adjunct treatment at the time of urethral dilation. The urethral stricture recurrence rate did not improve with the injection of AM despite the hypothesized benefits of anti-fibrotic and anti-inflammatory properties.