In response to a U.S. Food and Drug Administration (FDA) 522 study to test co-primary endpoints of superiority and noninferiority, researchers compared the safety and efficacy of transvaginal mesh repair versus natural tissue repair. The study compared transvaginal mesh to native tissue repair for treating pelvic organ prolapse in a prospective, nonrandomized, parallel cohort, multi-center trial. The primary endpoints were mixed treatment success at 36 months, which included anatomical success (defined as POP-Q points Ba0 and/or C0), subjective success (vaginal bulging as measured by the PFDI-20 [Pelvic Floor Distress Inventory]), retreatment measures, and rates of serious device-related or serious procedure-related adverse events. Quality-of-life assessments, mesh exposure, and mesh- and procedure-related problems were among the secondary endpoints, equivalent to the primary composite outcome but with anatomical success defined as POP-Q point Ba0 and/or C0. Again, the stratification of propensity scores was used.

The primary endpoint composite success rate was 89.3% (201/225) for transvaginal mesh and 80.2% (389/485) for native tissue repair at 36 months, demonstrating noninferiority by a margin of 12% (propensity score-adjusted treatment difference 6.5%, 90% CI 0.2 percent to 13.2%). The transvaginal mesh did not outperform natural tissue healing (P=.056) in the primary composite outcome. Transvaginal mesh was superior to native tissue healing using the secondary composite endpoint (P=.009), with a propensity score–an adjusted difference of 10.6% (90% CI 3.3–17.9%) in favor of transvaginal mesh. Subjective success was 92.4% for transvaginal mesh and 92.8% for native tissue restoration, with a propensity score-adjusted difference of 4.3% (CI 12.3% to 3.8%). For the primary safety endpoint, 3.1% (7/225) of transvaginal mesh (TVM) patients and 2.7% (13/485) of native tissue repair (NTR) patients developed serious adverse events, demonstrating that transvaginal mesh was non-inferior to native tissue repair (0.4%, 90% CI 2.7% to 1.9%). Overall, the TVM group had 35.1% (79/225) device-related and/or procedure-related adverse event rates, whereas the NTR group had 46.4% (225/485) (15.7%, 95% CI 24.0% to 7.5%). 

At 36 months, transvaginal mesh repair was not better than native tissue restoration for the treatment of anterior and/or apical vaginal prolapse. Subjective success, an essential factor in the patient experience, was high and did not differ statistically across groups. In terms of major device-related and/or serious procedure-related adverse events, transvaginal mesh repair was as safe as native tissue repair.