Mesh use in pelvic floor surgery
Surgical meshes have been used to repair abdominal hernias, stress urinary incontinence, POP, and colorectal functional disorders. Synthetic and biological meshes have been introduced to reduce the recurrence rates of POP surgery by providing support in patients with no fascia or very poor fascia.
The principle of using grafts in reconstructive surgery is to reinforce native tissue. Logically, mesh usage in women with a higher risk of recurrence should result in benefits which outweigh the risks, but there is no evidence thus far. The material must be safe, biologically compatible, and must provide both anatomical and functional results. The ideal material should be chemically and physically inert, non- carcinogenic, mechanically strong while remaining flexible, non- allergenic, non-inflammatory, and non-modifiable by body tissue. None of the meshes so far have satisfied all of these criteria and the ideal mesh is still awaited (68).Clinical outcome following mesh implantation is influenced by material properties, product design, overall mesh size, route of implantation, patient characteristics, associated procedures (e.g. hysterectomy), and the surgeon's experience (69, 70). Results of the large pragmatic parallel group multicentre RCT from the United Kingdom (PROSPECT study) comparing native tissue, biological (graft trial), and non-absorbable vaginal mesh (mesh trial) usage for anterior or posterior compartment repair surgery did not show any significant difference at the end of 2 years following surgery in the primary outcome of participant-reported prolapse symptoms. Results from the graft trial of the PROSPECT study state that women reporting the feeling of ‘something coming down' was higher in the graft (biological mesh) group compared to those who underwent native tissue repairs with a treatment effect size of 1.26 (95% CI 1.01-1.58) and a P-value of 0.04 at the end of the 2-year follow-up (71).
Mesh complications were seen in 12% of the women in the synthetic mesh arm at the end of the 2-year follow-up (71). Long-term follow-up of these women will shed more light onto the success rates and long-term complication rates.Mesh in POP surgery has been shown to be associated with complications such as infection, tissue extrusion, mesh exposure, organ perforation, mesh shrinkage, pelvic pain, and sexual dysfunction. Rare, but severe complications, including death, fistula formation, and mesh erosion into adjacent organs, have been reported in the Manufacturer and User Device Experience (MAUDE) database (72, 73). Following complications of mesh, litigation and law suits have resulted in the withdrawal of some mesh products from the market. NICE in its latest guidance on the use of transvaginal mesh in anterior or posterior vaginal wall repairs states that mesh has serious but well-recognized safety concerns and has to be used only in the context of research (74).
Scientific Committee on Emerging and Newly
Identified Health Risks opinion
The European Commission has requested the Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) to assess the health risks of meshes used in urogynaecology surgery. After a detailed review of evidence, SCENIHR concluded that it is important to consider the overall surface area of material used, the product design, and the properties of the material used. Mesh in POP surgery may be associated with higher morbidity due to the large amount of mesh used compared to that used in the surgical management of stress urinary incontinence. The use of mesh for the treatment of POP should only be considered in complex cases, in particular, after failed primary repair surgery. Mesh exposure rates for vaginal POP surgery with mesh range from 4% to 19% (75).
SCENIHR recommendations:
• The implantation of any mesh for the treatment of POP via the vaginal route should be only considered in complex cases in particular after failed primary repair surgery.
• Due to increased risks associated with the use of synthetic mesh for POP repair via a transvaginal route, this option should only be used when other surgical procedures have already failed or are expected to fail.
• Limiting the amount of mesh for all procedures where possible.
• There is a need for further improvement in the composition and design of synthetic meshes, in particular for POP surgery.
• The introduction of a certification system for surgeons based on existing international guidelines and established in cooperation with the relevant European Surgical Associations.
• Appropriate patient selection and counselling, which is of paramount importance for the optimal outcome for all surgical procedures, particularly for the indications discussed. This should be based on the results of further clinical evidence, which should be collected in a systematic fashion for all of these devices.
Scottish Independent Review of the use, safety and efficacy of transvaginal mesh implants in the treatment of stress urinary incontinence and pelvic organ prolapse in women
Vaginal mesh procedures have been suspended in Scotland from 2015 following a discussion in the parliament amid growing concerns on the safety of these procedures. An independent review has concluded that ‘In the surgical treatment of POP, current evidence does not indicate any additional benefit from the use of transvaginal implants (polypropylene mesh or biological graft) over native tissue repair. Transvaginal mesh procedures must not be offered routinely' (68, 76).