Results of First Boston Scientific Postmarket 522 Study Presented at AUGS 2018

Data presented at the 2018 AUGS annual meeting in Chicago demonstrated that the Solyx™ Single Incision Sling (SIS) System achieved treatment success, meeting all primary and secondary endpoints in a three-year study of 281 women with stress urinary incontinence (SUI). The trial also demonstrated that the Solyx SIS System was non-inferior to the gold-standard transobturator mid-urethral sling (TMUS) procedure for the long-term successful treatment of these patients.

“These findings provide a high degree of evidence supporting the safety and effectiveness of the Solyx SIS System, as compared to transobturator mid-urethral sling (TMUS) procedures, and reinforce the use of a minimally invasive procedure for SUI,” said Amanda B. White, MD, principal investigator, University of Texas Dell Medical School. “The results have the potential to impact millions of women with SUI by offering confirmation about the Solyx SIS System as a viable, first-line surgical treatment option for these patients.”

Study Design

This prospective, parallel cohort, post-market surveillance 522 study evaluated 281 patients at 21 sites over 36 months to compare efficacy and adverse events for non-inferiority of the Solyx SIS System versus TMUS performed using the Obtryx™ II Sling System. Inclusion criteria included stress predominant urinary incontinence per the MESA and positive cough stress test. Patients were required to undergo urodynamic evaluation, have a negative urine culture, and a PVR ≤150cc. Participants were not eligible if they had undergone prior SUI surgery or had a mesh extrusion.

Study sites were assigned to a cohort group, SIS or TMUS, based upon documented competency with the cohort device, and investigators participated in a training session to standardize technique. The primary endpoint was treatment success defined by a composite of objective measure (negative cough stress test) and any subjective self-reported improvement in SUI using the Patient Global Impression of Improvement (PGI-I) at 36 months. Secondary endpoints included adverse events and indication for reoperation or retreatment. A non-inferior margin of 15 percent and 10 percent was prespecified for the primary efficacy and safety measures, respectively. 


The results showed that the SIS group was non-inferior to the TMUS group in composite treatment success with both intention-to-treat (ITT) and per protocol analyses. At 36 months, the treatment success was 90.4 percent (94/104) in the SIS group and 88.9 percent (96/108) in the TMUS group (P=0.93), in the ITT population, based on available cases (Figure 1).
Results Figure 1
Rates of device- and/or procedure-related serious adverse events at 36 months in the SIS group were non-inferior to the TMUS group. Similar proportions of mesh-related complications, dyspareunia, pelvic pain and urinary retention were observed between the two treatment groups (Figure 2).
Results Figure 2

This study provides a long-term non-inferiority analysis between single incision sling and traditional TMUS, showing that SIS is not inferior to TMUS for long-term treatment success of SUI and that the rates of SAE following SIS are not inferior to SAE following TMUS. This study offers longer term efficacy and safety data on SIS, and may support more minimally invasive surgery for SUI.

Boston Scientific is completing three post-market surveillance 522 studies to fulfill U.S. Food and Drug Administration requirements, with the data on the remaining two studies expected in 2019.