The medicolegal challenges associated with pelvic mesh complications
Research published in October 2018 showed that 3.3% of mesh implants used for urinary incontinence cause complications requiring reversal operations. In this article, Dr Ivan Ramos-Galvez LMS, FRCA, FFPMRCA, Consultant in Pain Medicine and expert witness, discusses the history of the introduction of pelvic mesh treatment as a treatment for urinary incontinence and explores the reasons why complications occur and the pain conditions associated with these complications.
Urinary stress incontinence is a common problem that affects women of all ages, more commonly after childbirth. The cardinal symptom is leakage of urine when the bladder is submitted to any pressure. This may involve anything from a few drops of urine when running to catch the bus, to leakage on coughing, sneezing or laughing.
Traditionally the management was conservative involving physiotherapy to reinforce the pelvic floor muscles and life-style changes to reduce exposure to the triggers. Unfortunately, these treatments are not always effective and the symptoms can be embarrassing and have a significant and negative impact on daily life; as a result, surgical techniques were developed.
The surgical techniques to resolve the problem were safe, well tried and tested over time, and offered reasonably good outcomes. However, they were not always without complications, the most common being recurrent incontinence, as well as more general complications relating to potential tissue trauma and infection, as can be associated with any surgical procedure.
In the mid 1990s a new technique for the surgical treatment of urinary incontinence was developed. It involved a monofilament of polypropylene made into a mesh that could be inserted percutaneously under local anaesthetic. The concept was based on the theory that lifting the mid urethra up could offer the resistance required to stop passive leakage of urine. The technique had many perceived advantages:
- The mesh was inserted under local anaesthesia and therefore allowed an intra-procedure cough test to ensure that the incontinence had been successfully treated.
- It avoided the risks of a general anaesthetic.
- It was a quick procedure which could be carried out within a day (20 minutes operative time) because it was percutaneously inserted, with fast recovery to normal life afterwards.
These benefits expedited the regulatory process and the “kits” became widely distributed. Further kits became available and their sale was authorised based on their similarity to the original product, rather than pure efficacy and safety.
Guidelines for the management of stress incontinence evolved to incorporate the new mesh treatment and older surgical methods became obsolete. Technical skills relating to the previous, more invasive surgery were lost and a new generation of “mesh surgeons” were trained. The results were promising, offering curative rates of 85%, based on cough tests, change in weight of a sanitary pad over 24 h, urodynamics and Visual Analogue Score of urinary symptoms (0=none and 100=unbearable). Overall, studies that now run to a 15 year history still report the same results, suggesting low risk of complications.
However, the technique involves a blind percutaneous transvaginal insertion of a trochar (a surgical instrument) directing it towards the iliac fossa in one side, ensuring it is positioned at the level of the mid urethra and then towards the iliac fossa on the other side. A modification involves a change in direction towards the obturador foramen in a more horizontal trajectory. The pitfalls are that the insertion involves passage of a large trochar incorporating a foreign material through a non-sterile cavity into the deep tissues of the pelvic floor. Structures on the way include bladder, muscles, nerves and bowel. Bladder perforations are relatively common and cystoscopy is routinely carried out to ensure the placement of the mesh avoids the bladder. Overall in the short term there is a risk of infection of an implanted foreign material, bladder/bowel perforation and nerve trauma/damage.
The initial studies reviewing the outcomes never considered or reported the incidence of pain. They concentrated on the outcomes in urological symptoms and satisfaction with regards to incontinence.
Unfortunately, some women develop pain which can be very intrusive to their lives; often more so than the incontinence they were trying to treat. On reporting the pain to the surgeon, many women have felt dismissed, initially being advised it is as a result of the recent surgery and later, by underplaying it in comparison to curing the incontinence. Time has shown that meshes have been found to be coated in bacteria and when loaded with the weight of the abdominal organs transforms itself into a cutting thread, akin to the handle of a heavily loaded plastic bag.
Furthermore ,the polypropylene material the mesh is constructed from has physical and chemical properties that change with time and temperature, akin to plastic containers used to reheat meals in a microwave. These changes include twisting, curling, contraction and even rupture of the mesh itself. In the short term, bladder infections that require prolonged courses of antibiotics, nerve damage and muscle dysfunction are seen. In the long term, antibiotic resistance, fistulae, chronic pain, mesh cutting into the vagina and bladder, dysfunction of the pelvic muscles, loss of sexual function, bladder incontinence, bowel incontinence, constipation, depression, anxiety, social withdrawal and isolation and a loss of confidence… are all reported symptoms. These late complications have been reported after years of successful results with no prior problems.
It is a complex problem that has a complex solution. The obvious one is removal of the mesh without any further harm being caused. Mesh removal is challenging, laborious and very skilled. Patient selection is key. Not all patients who experience complications from mesh insertion are suitable to have the mesh removed. When meshes have been removed, 100% of these meshes have shown histopathology in keeping with a graft versus host reaction that suggests activation of the immune system as mediator of a systemic inflammatory reaction. This may account for the patients who report symptoms associated with the onset of autoimmune diseases, widespread arthritis and even fibromyalgia following mesh surgery. The treatment for women facing this worrying and painful situation is a multidisciplinary approach comprising of self-help techniques, psychological help and above all feeling listened to and supported.
Monofilament of polypropylene is used in a mesh format for other procedures such as in the repair of prolapses and although not in the same numbers have, over time, given similar type of complications.
The final and most common use of mesh is a mesh hernia repair. Neuropathic pain is a common complication in hernia surgery and it can develop at any time from immediately post-operatively to years afterwards. The nerve pain these patients feel is often in the groin and low abdomen and testicles. Although severe, the overall symptoms are of a lesser level of impairment to the overall quality of life compared to the incontinence mesh.
Class Action suits against the manufacturers of the mesh kits in the US have seen significant claims for compensation and an increasing number of claims are being brought by women individually and as actions groups. A Consultant in Pain Medicine is well placed to assist with a medico legal claim of this type which often involves complex chronic pain and associated conditions such as fibromyalgia. Dr Ivan Ramos-Galvez, author of this article, has provided expert opinion on these cases. He is a well-established pain expert, specialising in the diagnosis and treatment of complex pain conditions. He is well regarded as an expert witnesss in cases involving fibromyalgia and other pain conditions.
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