Factors to Consider in Augmentation Urethroplasty with Oral Mucosa Graft or Penile Skin Flap for Anterior Urethral Stricture: A Systematic Review and Meta-analysis

CONTEXT: Oral mucosa graft (OMG) and penile skin flap (PSF) are common substitutions in urethroplasty; however, the recommended substitution for anterior urethral strictures remains uncertain. OBJECTIVE: To compare the efficacy of OMG and PSF in anterior urethral strictures in terms of success rate and prevalence of postvoid dribbling based on current studies. EVIDENCE ACQUISITION: A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) and registered at PROSPERO (ID: CRD42022313879). All publications until March 1, 2022, were searched in the PubMed, EMBASE, and Cochrane Library databases without any restriction. Studies that focused on patients with anterior urethral strictures undergoing single-stage augmentation urethroplasty with OMG and PSF, and reported comparable success rates between the two substitutions were included. EVIDENCE SYNTHESIS: Thirteen studies involving a total of 1216 patients were included in the screening procedures, and 12 studies were eventually included in the meta-analysis. No significant difference in success rates was identified between OMG and PSF (odds ratio [OR]: 1.41, 95% confidence interval [CI]: 0.96–2.07, p = 0.08). No significant difference was observed in the comparison of success rates in penile urethral strictures (OR: 0.95, 95% CI: 0.53–1.70, p = 0.86) and in the comparison of postvoid dribbling (OR: 0.59, 95% CI: 0.31–1.11, p = 0.10). However, a subgroup analysis suggested that OMG had a higher success rate than PSF in studies with the top 50% sample size (six studies, OR: 1.678, 95% CI: 1.055–2.668, p = 0.029) and the top 50% follow-up period (five studies, OR: 2.279, 95% CI: 1.193–4.352, p = 0.013). CONCLUSIONS: OMG provides the same success rate and postvoid dribbling as PSF. However, based on the existing evidence, OMG is more likely to perform better in a cohort with long-term follow-up and a relatively large sample size. More studies on the two substitutions are necessary to evaluate the factors of urethroplasty success rate, performance of substitutions in penile urethral strictures, and indicators of quality of life. PATIENT SUMMARY: In this research, we compared the outcomes of oral mucosa graft (OMG) and penile skin flap for urethroplasty in anterior urethral stricture patients in 13 studies. We found that these were similar in terms of success rate and postvoid dribbling. However, OMG could probably provide a higher success rate when the studies had more patients or a longer follow-up period.