In their paper “Vaginal mesh for incontinence and/or prolapse: caution required!” doctors Phillipe Zimmern and Ginger Isom-Batz discuss ‘the dark side of mesh’. They argue that procedures involving mesh may seem simple and easy to perform but could nevertheless have long-term consequences for patients.
They state that many new products have been allowed onto the market despite limited knowledge regarding their safety and long-term efficacy. The success of these devices is due to the clever marketing of the mesh kits which require limited training, and the FDA clearance process which allows products to come onto the market with apparent ease.
Polypropylene mesh, known as ‘prolene’, is the most common of the synthetic materials used in pelvic surgery. It is now used in slings to treat incontinence and also in repairs which use larger amounts of prolene to treat prolapse of the bladder, bowel or vaginal vault.
The authors note that there is a lack of evidence-based data regarding the safety and efficacy of these meshes. Some studies have reported vascular and bowel injuries including 8 deaths, which show that serious complications can occur. Other studies report vaginal erosions, bladder and urethral perforations and erosions, urgency, changes in flow rate and flow pattern and complete obstruction.
The transobturator tape (TOT) was marketed and introduced as safer than the TVT because of the way the side ‘wings’ are introduced through the obturator fossa instead of the retropubic space, supposedly reducing the chances of vascular, bowel or bladder injury. However, several serious complications have been reported already. Some studies have described debilitating thigh and groin pain, infections of the tape causing sinus draining or even thigh necrotizing fasciitis. There have been two reported cases of death after the TOT procedure due to vascular injury.
In prolapse repair, mesh has been used either as a primary repair or in cases of prolapse recurrence. Reports of vaginal erosions after this procedure have varied from 0 to 18% with short-term follow up. Painful intercourse has also become a serious concern, with a recent study reporting 38% and calling for surgeons to stop using prolene mesh to repair bladder and bowel prolapse.
The authors note that the removal of these meshes, either partially or completely, via the vagina or abdomen, has proved “a significant challenge”. There have been reports of vesicovaginal fistulas forming after mesh removal. They argue that even if the rates of these debilitating complications are quite low, they are “life-changing for the patient, sometimes irreversible and often sources of litigation”. Many women would have preferred to live with some incontinence or prolapse rather than live with chronic pain, suffer from fistulous tracts and undergo numerous unhelpful treatments and procedures.
Zimmern and Isom-Batz declare that they are not alone in their concerns regarding the “rampant use of vaginal mesh” in pelvic floor reconstruction.
The authors note that it is still not certain how the aging vaginal tissues will respond to synthetic material just under their surface and this should be a consideration in younger women and in those desiring to remain sexually active.
For the midurethral tape, they have seen some delayed onset of urge and urge incontinence symptoms resulting from a kinking effect in the midurethra with urethral and bladder neck ballooning. Removal of the tape does not always result in an improvement in bladder dysfunction. Also, midurethral compression from the tape can lead to ischemia resulting in a permanently scarred and narrowed urethral lumen after tape excision.
In pelvic organ prolapse, meshes to repair cystoceles are placed directly under the bladder trigone. Erosions into the bladder could result in a serious risk of injury if the mesh subsequently needed removing. There is also the concern that these permanent materials may move over time and become exposed in the urinary tract, causing pain or bladder dysfunction.
The authors note that when a new drug is introduced onto the market and receives FDA approval, several safety and efficacy trials will have already taken place but no such a mechanism exists to test new surgical devices. They conclude that there is no mid or long-term data on the efficacy and safety of vaginal meshes for prolapse and that doctors must demand higher standards and not agree to use a product based on small, short studies published without peer review.
Ref: Zimmern & Isom-Batz, Expert Review of Medical Devices, September 2007, Vol. 4, No. 5, Pages 675-679