This blog provides an overview of surgical mesh complications in Scotland, the Scottish Government’s action on this issue, and outlines the need for more information.
Surgical mesh (also known as tape) is a synthetic material that is implanted in the body to support weakened or damaged tissue. Surgical mesh implants have been used to treat hernias, stress urinary incontinence (SUI), pelvic organ prolapse (POP), and rectal prolapse. Many patients have benefitted from these surgeries, but some patients have experienced serious, life-changing complications.
Materials used in mesh procedures
Non-absorbable surgical meshes are made of plastics such as polypropylene or polyester (see image). The mesh is affixed to the patient’s natural tissue using sutures or small titanium ‘tacks’. The intention is that the mesh causes a biological reaction (a ‘foreign body’ reaction) when implanted, so that the patient’s tissue grows into the mesh to strengthen the repair.
The plastics used in surgical mesh are also routinely used in permanent surgical stitches. Mesh materials are physically and chemically inert and non-toxic.
Titanium is also widely used in other surgeries, and is considered to be the most ‘biocompatible’ metal (i.e. is not harmful to human tissue). It is commonly used in implants such as hip replacements.
Surgical meshes and tacks are medical devices. Their regulation includes initially determining they are safe and fit for their intended purpose, followed by ongoing monitoring. Medical device regulation is a reserved matter, and is performed by the UK Medicines and Healthcare products Regulatory Agency (MHRA). Healthcare professionals and patients can report safety concerns about medical devices to the MHRA Yellow Card Scheme. Further information is available in a SPICe briefing on the regulation and governance of medical devices in Scotland.
The development of surgical mesh techniques
Surgical mesh has been used since the 1950s to repair hernias. Before this, hernias were repaired by suturing natural tissue together to repair the defect. The sutures pull the muscles on either side of the defect together, creating tension in the area.
However, hernias often occur in areas of tissue weakness, meaning that the sutures used in a natural tissue repair might not hold well, leading to hernia recurrence (British Hernia Society, 2018). Techniques involving surgical mesh were developed to eliminate or minimise the tension that could lead to repair failure.
There is strong evidence that using mesh in hernia repair does indeed reduce recurrence. Two Cochrane systematic reviews (from 2012 and 2018) found that groin hernia repairs that used mesh markedly reduced the likelihood of the hernia recurring, compared with natural tissue techniques.
Surgical mesh has become the preferred method of hernia repair worldwide. Nonetheless, a small minority of surgeons prefer to use natural tissue repair, and only use mesh as a last resort (e.g., surgeons from Shouldice Hernia Hospital, Canada).
Following its success in minimising hernia recurrence, surgical mesh began being used for repair of pelvic organ prolapse (POP) in the 1970s. The first such surgeries were transabdominal (through the abdomen), with transvaginal (through the vagina) mesh POP repairs starting in the 1990s. Transvaginal mesh repairs for stress urinary incontinence (SUI) also began around this time (US Food and Drug Administration review, 2011).
Stress Urinary Incontinence and Pelvic Organ Prolapse
In 2008, the US Food and Drug Administration (FDA) alerted health practitioners of “rare” reports of complications following POP and SUI repairs using TVM. Complications reported by women included infection, pain, urinary problems, mesh erosion through the vagina wall, sexual pain, and decreased quality of life.
In 2011, after monitoring outcomes and conducting a review, the FDA amended its 2008 conclusion, stating that “serious adverse events are NOT rare” in TVM POP repairs.
In 2014, petition PE1517 was lodged with the Scottish Parliament on behalf of the Scottish Mesh Survivors “Hear Our Voice” campaign. The petitioners called on the Scottish Government to suspend TVM procedures. The petitioners stated:
“Globally, tens of thousands of victims have suffered life-changing side effects, with many ending up in wheelchairs, enduring multiple organ trauma and extensive nerve damage.”
A survey of Sling The Mesh campaign members – individuals interested in raising awareness of surgical mesh complications – highlighted quality of life implications following mesh surgery. In the survey, individuals who had had mesh surgery (whether for POP, SUI, hernia, rectal prolapse or another condition) reported the following issues:
- Irreversible pain.
- Depression and suicidal ideation.
- Having to give up work or reduce hours worked.
- Mobility issues, requiring a stick, mobility scooter or wheelchair.
Scottish Government action
In 2014, the Scottish Government asked health boards to consider suspending the routine use of TVM for SUI and POP procedures, until an independent review reported its findings. Boards were asked to consider the evidence for the effectiveness of TVM compared to more traditional surgical and non-surgical treatment options.
In 2017, the independent review on TVM implants in Scotland was published. Among its recommendations, the review concluded TVM mesh should not be the default repair procedure for SUI or POP.
The Scottish Government went on to set up a £1 million Mesh Fund to help towards costs incurred by women affected by mesh complications in 2021, and the Scottish Parliament passed the Transvaginal Mesh Removal (Cost Reimbursement) (Scotland) Act 2022. A Complex Mesh Surgical Service was established to provide surgical expertise for women seeking transvaginal mesh removal.
Number of procedures in Scotland
Public Health Scotland data on transvaginal mesh procedures for 2009-10 to 2018-19 (see below) show that all surgeries for SUI and POP (mesh and non-mesh combined) markedly decreased over this 10-year period, and that transvaginal mesh (TVM) procedures decreased even more substantially. Both declines started before the routine use of TVM was halted in 2014. The decline in all SUI or POP surgeries may reflect a growing focus on non-surgical treatment options, such as lifestyle change, physiotherapy, or pessaries (NHS patient information for POP and SUI).
As shown below, in 2009-10 92% of SUI repair procedures (1,834) used TVM; this decreased to 7% (34) by 2018-19. For POP repair procedures the proportion using TVM fell from 11% (381) to 0% (fewer than five surgeries). The transabdominal technique of mesh insertion began to be used for a larger proportion of POP repairs over this period.
Other surgical procedures using mesh
Number of procedures in Scotland
Between 2015-16 and 2019-20 hernia repairs accounted for around 1% of all procedures in NHS hospitals in Scotland (approximately 10,500 per year on average). Mesh was used in 62% of these hernia repairs (approximately 6,500 per year on average). (Data: Public Health Scotland and Scottish Health Technologies Group).
Between 2015-16 and 2018-19 in Scotland, around five times as many hernia repair procedures were performed as SUI and POP repair procedures combined (see below).
Data for rectal prolapse procedures (rectopexy) using mesh are not published in Scotland. English data indicate there were 180 times as many inguinal hernia repairs using mesh in 2020-21 than there were rectopexy procedures using mesh, suggesting that this procedure would also be much less common in Scotland.
In 2021, petition PE1865 was lodged with the Scottish Parliament, calling for the Scottish Government to suspend the use of all surgical mesh and fixation devices. The petitioners highlighted the fact that mesh complications are not isolated to TVM procedures: some hernia and rectal prolapse mesh patients are also suffering similar complications.
The 2021 SHTG Review on hernia mesh reported the most common adverse events following mesh-based hernia repair are pain, infection, hernia recurrence, adhesion (scar tissue forming between separate surfaces of the body), and blockage (obstruction) of the bowel.
The Citizen Participation and Public Petitions Committee (‘the Committee’) is currently considering petition PE1865. It has heard from individuals who had mesh implanted during hernia or rectal prolapse repair surgery. Complications described by individuals included: chronic pain, infection, nerve damage, faecal incontinence, urinary incontinence, and sexual pain.
Some individuals told the Committee they had been informed that the hernia or rectal prolapse mesh had eroded into their vagina wall, bowel and bladder, or adhered to their bladder, ovary, fallopian tube, or bone. Some individuals reported the complications had led to mobility issues and had significantly reduced their mental health and quality of life.
Some individuals making written submissions for petition PE1865 reported improvements since having mesh removal surgery, while others had been told by surgeons that the mesh was too enmeshed in their body to be removed without causing serious ramifications, such as the loss of their rectum or testicles.
Difficulties getting mesh removal surgery on the NHS were reported, which were attributed to a lack of knowledge about the issue in primary care, and the Scottish Complex Mesh Surgical Service only accepting gynaecological referrals. Some individuals resorted to going private to get their mesh removed, and some travelled abroad to do so.
The Chief Medical Officer Professor Sir Gregor Smith told the Committee that the Complex Mesh Surgical Service was a specialised service dealing only in TVM removal, as the team consisted of urogynaecologists, a urologist and colorectal surgeons. No similar service exists for the removal of other types of surgical mesh.
Scottish Government action
The Scottish Health Technologies Group (SHTG) were commissioned by the Scottish Government to assess the safety of surgical mesh in groin hernia repair in males (published 2020) and groin and abdominal hernia repairs in all adults (published 2021). The SHTG concluded that the available evidence supports the continued use of surgical mesh in hernia repair.
How common are mesh complications?
Any surgical procedure has a degree of risk: this should be communicated to patients along with potential benefits to enable them to make an informed choice about the treatment options available to them (NHS Education for Scotland).
Being able to weigh-up the risks against the benefits, however, requires a good understanding of the scale of the risks. Many witnesses told the Committee that current evidence about complications has not looked at the long-term impact, or considered important outcomes such as quality of life.
In the case of TVM complications, the 2017 Scottish Independent Review and the 2020 Cumberlege Review into medical device safety both concluded that the number of women suffering complications is not known, because there is currently no reliable information.
In the case of hernia mesh complications, the 2021 SHTG Review also highlighted “the uncertainty around long-term outcomes from hernia surgery, using mesh or non-mesh repair, given the few studies that followed up with patients beyond 1 year”.
The SHTG Review noted there are a small number of hernia mesh removal surgeries each year (32 per year on average, 2015-16 to 2019-20). Although this is only 0.5% of the mesh hernia repairs conducted each year, a petitioner argues it is likely to underestimate the scale of the need: “In my opinion the reason for few removals is we the patients don’t have a clear patient pathway. GPs aren’t aware of where to send us as there are no clear routes.”
There have been a number of calls for quantification of the scale of surgical mesh complications:
- The 2017 Scottish Independent Review on TVM concluded “The lack of long-term follow up and related outcome data, including information on quality of life and activities of daily living, should be addressed.”
- The 2021 SHTG Review on hernia mesh stated: “It is important that data on long-term outcomes from hernia repair in Scotland are recorded at a national level to inform future decision-making. This should be aligned with the UK Medical Device Information System and include collection of patient reported outcomes.”
- The 2020 Cumberlege Review called for substantial revision of the MHRA in relation to adverse event reporting and medical device regulation.
In June 2022, the Minister for Public Health, Women’s Health and Sport, Maree Todd, said the Scottish Government was working: “… to establish the medical device information system—MDIS—which will provide important surveillance and outcome information.” The Minister had previously said of this system: “That will enable NHS Scotland to follow cases through for a number of years, and we will have good quality data available to us.”
The 2017 Scottish Independent Review concludes it is imperative that all adverse events related to mesh surgeries are recorded and reported, so that the true scale of surgical mesh complications can be assessed and addressed. This will enable patients to weigh up risks and benefits in a truly informed way.
The Citizen Participation and Public Petitions Committee continues to consider petition PE1865 and will report in due course.
Elizabeth Richardson, Senior Researcher, SPICe