Single-incision sling found noninferior to retropubic sling in vaginal prolapse repair

Catherine A. Matthews, MD, FACS, FACOG

In this interview, Catherine A. Matthews, MD, FACS, FACOG, shares findings and insights from the recent study “A randomized trial of retropubic versus single-incision sling amongst patients undergoing vaginal prolapse repair.” Dr. Matthews is the division head and fellowship director of urogynecology at Wake Forest Baptist Health in Winston-Salem, North Carolina.

Please provide an overview of this study and its findings.

This trial included women who were undergoing native tissue vaginal repair of pelvic organ prolapse in any compartment. These women had objectively demonstrated stress incontinence with prolapse reduction. They either were symptomatic in terms of their stress incontinence or had evidence of occult stress incontinence. Seventy-five percent of people had symptomatic stress incontinence and 25% only demonstrated it with prolapse reduction. For all these women, we had advised that they have a concomitant mid-urethral sling at the time of prolapse repair. This study was a randomized trial of any full-length retropubic sling, sized from a bottom-to-top approach, compared to the adjustable Altis single-incision sling. The primary outcome was a composite outcome that was designed to both assess the impact on stress incontinence symptoms, but also the potential complication of urinary retention or voiding dysfunction, which of course comes about if the sling is too tight. The composite was bothersome stress incontinence symptoms, the need for stress incontinence retreatment, or the need for intervention for voiding dysfunction. What we found within the first year after surgery was that the single-incision sling was noninferior to the retropubic sling. We [used] a predetermined 12% noninferiority margin, and we had a 5% difference between the 2 slings, so it was well within that predefined noninferiority margin. Overall, the composite outcome was 20% in the retropubic arm vs 25% in the single-incision arm. And so there was a trend toward slightly better efficacy in the retropubic arm (based on persistent stress incontinence symptoms), but that again was not statistically significant. The single-incision sling was actually slightly more satisfying to patients than the retropubic. When we asked patients, in terms of their global impression of improvement with each sling, it was 71% for the single-incision and 67% for the retropubic. We really found from the study, clinicians who had wanted to potentially offer the safer alternative of a single-incision sling, we determined that in this circumstance, it was noninferior.

Were there any patient characteristics or surgical approaches within the study that seemed to favor 1 sling type over another?

That's a great question. We evaluated [whether there were] risk factors for surgical failure in either group, and what I can tell you is that we didn't have sufficient power to do extensive sub analyses, but from a pragmatic perspective of looking at which patients of mine seem to be better suited for a single-incision sling, certainly obese patients in whom retropubic passage may be more challenging, older patients in whom one does not want to incur any risk of a retropubic hematoma or other, more serious injury, these patients seem to do particularly well with a single-incision sling that's avoiding the potentially more complicated retropubic anatomy.

The study found a slightly higher rate of adverse events in the single-incision group, but although it wasn't statistically significant. Are there any specific complications you'll be looking at more closely in future research?

We found that there was a slightly higher rate of urinary tract infection in the single-incision arm compared to the retropubic. This is very difficult to tease out because of course, we had concomitant prolapse procedures and we did have a higher rate of colpocleisis in the single-incision arm, and it may be that it was just a true unrelated finding, because of the slight difference in the rate of colpocleisis in 1 group vs the other. We didn't do a block stratification for the type of prolapse repair; we did a block stratification in terms of symptomatic vs occult stress incontinence. But it's plausible that that observation was really because of the influence of the type of prolapse repair that was more common in 1 group than the other.

Beyond stress urinary incontinence, were there any other patient-reported outcomes, like pelvic organ prolapse symptoms, that differed between the 2 sling groups?

There was not, but the 1 other outcome that I was fascinated by and excited about was the impact of the sling on urgency symptoms. What we found in the study was that 75% of patients had significant urgency incontinence as well, and so this population was really being affected by both stress and urge incontinence. We found that with the prolapse repair and the placement of the sling that 50% of severe urgency completely resolved with surgical intervention. This is a significant talking point for patients, because we have a lot of women with anterior apical prolapse [for whom] the chief complaint is really of urgency incontinence. And sometimes we're almost reluctant to offer surgery, because we think, well, maybe that's not really going to help that symptom. But on the basis of this study, showing that just over 50% had complete resolution of the severe urgency with the prolapse repair and with the sling, I'm more likely to recommend concomitant sling placementon the basis of that outcome. We had a low rate of de novo urgency, so only about 6% of patients had new symptoms of urgency. Of course, some patients had persistent urgency, but if you have persistent urgency after prolapse repair and a sling, that's when I think medications would be more effective. That's the patient-reported outcome that I think was unexpected and very exciting.

Given these results, do you see the single-incision sling becoming the preferred choice for patients undergoing vaginal repair with stress urinary incontinence?

I think this is always going to be a surgeon choice, and this paper can't tell me which one is really preferred. But there is no question that there is a trend toward a lower serious adverse event rate among single-incision slings. We had a very low rate of serious adverse events, but the 1 serious adverse event that was unique to the slings was a large, retropubic hematoma in the retropubic arm that required interventional radiology intervention to stop the bleeding. If you have that complication from a quality-of-life intervention, it's something that no surgeon wants to deal with. So knowing that there's equivalence demonstrated, I do think that more surgeons are going to choose single-incision slings in th circumstance, because it is less risky in terms of serious adverse events. We didn't show that statistically in this trial. But that's because rare events are never going to be evaluated statistically in a randomized trial. I think that large meta analyses might demonstrate that, and we know from just the stress incontinence literature that single-incision slings have lower risks of bleeding, nerve injury, [and] vascular injury. So I think that generally speaking, they're safer. To answer your question, very shortly, I do think that many surgeons with these data would then say, "My preferred [approach] with a concomitant native tissue repair is going to be a single-incision sling."

REFERENCE

1. Matthews CA, Rardin CR, Sokol A, et al. A randomized trial of retropubic versus single-incision sling amongst patients undergoing vaginal prolapse repair. Am J Obstet Gynecol. 2024 May 3:S0002-9378(24)00562-3. doi:10.1016/j.ajog.2024.04.036