Midurethral sling operations for stress urinary incontinence (SUI) are safe, and – regardless of the routes traversed – are highly effective in the short and mid term, according to a new Cochrane systematic review.
Evidence showing long-term effectiveness is also accruing, but too few of the existing trials have reported outcomes beyond 5 years, Dr. Abigail A. Ford of Bradford (England) Royal Infirmary and her colleagues from the Cochrane Incontinence Group reported.
The findings, based on a review of 81 trials involving a total of 12,113 women, were published July 1 (Cochrane Database Syst. Rev. 2015 [doi:10.1002/14651858.CD006375.pub3]).
Moderate-quality evidence indicates that the transobturator route and retropubic route provide similar rates of subjective and objective cure at up to 1 year (relative risk, 0.98 for both). Low-quality evidence suggests the subjective cure rates are similar with these two approaches at between 1 and 5 years (RR, 0.97), and moderate-quality evidence suggests the subjective cure rates are similar beyond 5 years with the two approaches (RR, 0.95), the investigators said.
Overall, about 80% of women undergoing surgery using either approach experience significant improvement in symptoms at up to 5 years after the surgery; that drops to about 70% after 5 years, based on the few studies that followed patients that long.
Although the overall adverse event rate was low, morbidity rates were higher with the retropubic route. For example, the rate of bladder perforation was 0.6% with the transobturator route vs. 4.5% with the retropubic route. Major vascular/visceral injury, mean operating time, operative blood loss, and hospital length of stay were all lower with the transobturator route. Further, voiding dysfunction was less common with the transobturator route (RR, 0.53).
Groin pain was more common in women in the transobturator vs. retropubic groups (6.4% vs. 1.3%), but suprapubic pain was less common (0.8% vs. 2.9%); both types of pain were of short duration.
The Cochrane investigators also found moderate-quality evidence for the following.
The overall rate of vaginal tape erosion, exposure, or extrusion was low (24 per 1,000 and 21 per 1,000 procedures for the transobturator and retropubic routes, respectively (RR, 1.13).
A retropubic bottom-to-top route was more effective than a top-to-bottom route for subjective cure (RR, 1.10).
Subjective cure rates in the short and mid term were similar when transobturator tape was passed using a medial-to-lateral or lateral-to-medial approach (RR, 1.00 and 1.06, respectively).
Voiding dysfunction was more common with the medial-to-lateral approach (RR, 1.74), but vaginal perforation was less frequent in the medial-to-lateral route (RR, 0.25).
It was unclear, due to very low-quality evidence, whether the lower rates of vaginal epithelial perforation affected vaginal tape erosion, the investigators noted.
The investigators reviewed the literature from 1947 up to June 2014, including only randomized and quasi-randomized controlled trials involving women with stress urinary incontinence, urodynamic stress incontinence, or mixed urinary incontinence, which contribute to up to 80% of cases of urinary incontinence.
They noted that concerns regarding mesh erosion are ongoing, but that the latest white paper and safety communications on meshes released by the Food and Drug Administration in 2011 “relates to ongoing concern with mesh used to treat pelvic organ prolapse and not the small strip of mesh/tape/sling used to treat SUI. In fact, the FDA states that the safety and effectiveness of midurethral slings is well established in clinical trials with 1-year follow-up.”
Overall, the current review highlights the positive impact that midurethral sling operations have on quality of life in women with stress urinary incontinence, but additional reporting of long-term outcomes is needed, the investigators wrote.
“We need to know more about what happens to women in the long term,” Dr. Joseph Ogah, one of the Cochrane investigators and a consultant gynecologist at the University Hospitals of Morecambe Bay NHS Foundation Trust in Cumbria, England, said in a statement. “This review found 35 trials carried out more than 5 years ago: If all the women in these trials were followed up, we would know much more about how long the operations last and, crucially, whether they had developed late but important side effects. Rather than starting any new trials in this area we need to obtain long-term follow-up from the existing trials.”
The review was supported by the National Institute for Health Research in the United Kingdom. Some of the review authors reported industry sponsorship to attend scientific conferences.