Midurethral vaginal slings (MUS) can be placed by retropubic or transobturator route to treat stress urinary incontinence. Despite the well-documented long-term efficacy, several complications have been reported in the literature including vaginal exposure, extrusion, dyspareunia, voiding difficulties, recurrent urinary tract infections, bleeding and pain, all of which are infrequent and usually easily managed.
Complications of MUS were first documented in 1998 following its launch on the market. However, in the last 3 to 5 years the media coverage has promoted and stimulated government attention in several countries leading to the withdrawal of the MUS from the markets in those countries. Such decisions are more political than clinical and have withdrawn women from the benefit of a well-documented minimally invasive effective anti-incontinent treatment. This has left many with limited, somewhat obsolete choices of more invasive surgery such as Burch colposuspension and/or autologous fascial slings.
Sadly, the governments have left clinicians and the majority of incontinent women disappointed and without a clear answer. The most common question is “how and why has this happened?” The MUS operation is to date the most studied anti-incontinence procedure with 17 years long-term efficacy as well as safety data reported in the scientific literature. Furthermore, more than 10 million women worldwide have received mid-urethral slings to date.
In 2018, Professor Linda Cardozo, a renowned expert and opinion leader in urogynaecology, in an interesting editorial published in the BJU, questioned “why have TVTs suddenly fallen into disrepute?” and highlighted the fact that surely, so many women and their healthcare advisors can’t all be wrong.
All national and international scientific societies including the British Society of Urogynaecology (BSUG), British Association of Urological Surgeons (BAUS), NHS England, Scottish Independent Review (SIR), National Institute for Health and Care Excellence (NICE), International Urogynecology Association (IUGA), American Urogynecologic Society (AUGS), American Urologic Association (AUA), Society for Urodynamics and Female Pelvic Medicine and Urogenital Reconstruction (SUFU), Royal Australian and New Zealand College of Obstetricians and Gynecologists (RANZOG), European Association of Urology (EAU), American Congress of Obstetrics and Gynecology (ACOG), Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) as well as the US Food and Drug Administration (FDA) have echoed the efficacy, safety and important clinical role of MUS in the treatment of stress urinary incontinence in women.
Despite this, in several countries governments have continued the pause on the use of MUS, and in UK regional mesh removal centres have now been created. The perceived high complication rate, brought about by a group of vocal campaigners and fuelled by the press, seems to have overcome the clinical evidence and the recommendations of national and international scientific professional societies in the field of female urinary incontinence.
Post-operative persistent pelvic pain has been the driving factor leading to the embargo on MUS. The incidence of urogenital pain after MUS placement varies from 0–30%. It has been proposed that the polypropylene prosthetic material in the MUS is associated with the risk of periprosthetic retraction phenomena and inflammatory reactions that may be responsible for pain.
However, if pain is the main reason for banning MUS (from either polypropylene or other surgical techniques), then both Burch colposuspension and autologous fascia slings should also be avoided and not recommended as polypropylene sutures are frequently used as a component of the sling and insertion techniques are similar.
Pain is the result of vascular, nerve and/or organ damage. Anatomically many blood vessels run through the space of Retzius as well as in the obturator fossa. Just on chance alone there is a risk that these vessels may be damaged during the placement of sutures on the ileopectineal ligaments when a Burch colposuspension is performed or with the passage of the trocars during the insertion of either a fascial or polypropylene sling. This may result in haematoma formation and pain in either procedure.
Persistent post-operative pain is also a well-described complication of Burch colposuspension leading to the introduction of the term "post-colposuspension syndrome" in 2002 to describe intractable suprapubic pain directly over the iliopectineal ligaments. This is due to the increased risk of developing osteitis pubis, irritation of the obturator nerve because of topographic proximity between the obturator nerve and operating field following colposuspension. Furthermore, it has also been reported in the scientific literature that about 1 in 20–50 women find sex uncomfortable or painful after a colposuspension.
Nerve injury again is a risk for all anti-incontinence procedures with the pudendal, ilioinguinal and iliohypogastric nerves being most at risk. The pudendal nerve in the pudendal canal divides into the perineal nerve and the dorsal nerve of the clitoris (DNC). Anatomical studies have identified that the DNC can be surgically injured under the pubic symphysis at the union of the two crus of the clitoris and on the dorsal surface of the clitoral body. Incorrect sling placement, synthetic or autologous, can therefore result in pain from entrapment/injury of the DNC.
In conclusion, if MUS should be abandoned because of pain, should autologous fascial slings as well as Burch colposuspension also be banned? The surgical approach is very similar, and the potential risk of intraoperative nerve and vascular injuries is the same and synthetic components of both are the same, so how are governments allowing one and not the other? While we are at it, governments should consider banning the use of polypropylene suture at the time of a colposuspension.
While complete or partial removal of a MUS is often the outcome of post-operative pain, the subsequent issue to consider is what to do if there is a recurrence of SUI. If autologous fascial sling is the proposed ‘salvage’ procedure, is there a risk of recurrence of pelvic pain in the cohort for which this was the original indication for removal?
Some of our logic is fuzzy at best and some of our suggestions meant to be taken with a grain of salt and some humour but, in our opinion, clinicians and patients (not governments) should make informed decisions about their care according to the best evidence available. Governments, media, vocal campaigners and legal firms should in our opinion not interfere.
As previously said, the USFDA has echoed the efficacy, safety and important clinical role of MUS and has recognized that polypropylene has been used safely and effectively in most surgical sub-specialties over the past 5 decades. Therefore, we respectfully disagree with the views of certain lawmaker, lawyers and campaigners and “anti-mesh” healthcare providers and, based on the data reported in the literature, we believe that the use of polypropylene MUS for stress urinary incontinence should be considered safe and effective.
In 2018, Prof. Linda Cardozo in her editorial published on the BJU concluded that “TVT should continue to be offered as a choice for women seeking surgery for their stress urinary incontinence”. Four years later, nothing has changed. Mid-urethral slings remain a memory in several countries and women are left with more invasive surgeries as their only option.
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Digesu, G.A., Bhide, A.A. & Swift, S. Mid-urethral sling and the mystery of pain. Int Urogynecol J 33, 749–750 (2022). https://doi.org/10.1007/s00192-022-05192-8