Mini-slings on par with mid-urethral slings for female SUI

In terms of patient-reported success, the newer, adjustable, anchored single-incision mini-slings (SIMS) were noninferior to the synthetic, tension-free, standard mid-urethral slings (SMUS) for the surgical management of stress urinary incontinence (SUI) in women, the SIMS study suggests.

“The percentage of patients reporting success remained similar in the [SIMS and SMUS] arms at 36 months,” said the researchers. The respective rates were 72 percent and 67 percent (adjusted risk difference, 5.7 percentage points).

These rates follow those seen at 15 months after randomization (79 percent vs 76 percent; adjusted risk difference, 4.6 percentage points; p_{noninferiority}<0.001). [N Engl J Med 2022;386:1230-1243]

 

Safety

“[However,] the safety of mesh devices has been the subject of substantial scrutiny over the past decade, owing to reports of adverse events (AEs) during extended follow-up, including tape or mesh exposure, groin or thigh pain, and dyspareunia,” the investigators noted.

The current study did show higher rates of dyspareunia with SIMS vs SMUS (12 percent vs 5 percent; p=0.01), but there were similar fractions of women reporting groin or thigh pain (14 percent and 15 percent), having tape or mesh exposure (3 percent and 2 percent), and having further surgery for SUI (2 percent and 1 percent).

“[The trial] was performed during heightened public debate about mesh devices; hence, patients and clinicians were unlikely to have underreported AEs,” said the researchers. And despite the ensuing legal battles and product withdrawals from the market, the investigators noted that the “trial compared two types of slings … and not specific devices, [and] most patients received devices that are still on the market.” [BMJ 2016;353:i3045; Cochrane Database Syst Rev 2014;6:CD008709]

 

Subjective vs objective measures

The trial involved 600 women (mean age 50 years) from 21 UK hospitals who had predominant symptoms of SUI and have failed or declined conservative treatment. They were randomized 1:1 to receive either SIMS or SMUS and were followed for 36 weeks to determine patient-reported success*.

“[While] we had limited data on objective success … patient-reported outcomes better reflect patients’ experience than objective measures, which can overestimate the success of surgery for SUI,” the researchers noted.

Of note was the proportions of women reporting a ‘cure’ (ie, no urinary leakage) with SIMS and SMUS (39 percent and 33 percent) on post hoc analysis. “[This is] a key point from this trial,” said Drs Ingrid Nygaard and Peggy Norton from the University of Utah School of Medicine, Salt Lake City, Utah, US, in an accompanying editorial. [N Engl J Med 2022;386:1280-1281].

“[However,] the success of a continence procedure depends on its definition, which can include various subjective and objective measures or a combination of measures,” they continued.

 

The bottomline: having two good alternatives

“Historically, women who were considering surgery for SUI faced wide abdominal incisions, inpatient hospitalizations, and a 6-week recovery period. Two decades ago, the introduction of [SMUS] … resulted in shorter recovery than traditional procedures with similar efficacy,” said Nygaard and Norton. With the emergence of the third-generation SIMS, which can be used without general anaesthesia, possible abdominal injury may be avoided, they added.

“The bottomline of this trial is that women affected by SUI have two good options, if available to them, for outpatient surgical management with 1- to 2-week recovery periods,” commented Nygaard and Norton. “This trial provides evidence that mesh surgeries for SUI are safe and effective — data that are important both for restoring confidence in such surgeries and potentially for increasing their availability.”

As the study was not sufficiently powered to identify important differences in AEs, longer-term data are warranted to evaluate for late-onset AEs and a potential decline in efficacy over time. Other limitations that should be taken into context are the follow-up period, lack of blinding, and exclusion criteria**.

Despite its suspension in the UK since 2018, SMUS continue to be the mainstay in clinical guidelines in the UK, the US, and Europe for the surgical management of female SUI.