Mesh has been used as a material to repair hernias for over 50 years. Before that time, hernias were closed using suture repair. In 1958, Francis Usher published his research, outlining a technique he developed using polypropylene mesh. Polypropylene is a thermoplastic polymer that is often used in packaging and labeling, textiles (such as ropes, carpets, and thermal underwear), plastic parts, reusable containers, laboratory equipment, as a composite hernia mesh, and more. Polypropylene ranks as the the world’s second most produced synthetic plastic. But is it safe to use in the body, and does composite mesh do more harm than good for hernia patients?
What is a hernia?
Hernias happen when fatty tissues or an organ pushes through muscle or connective tissue. Hernias are caused by muscle weakness or strain - or a combination.
How are hernias repaired?
- Tension repair: An incision is made in the abdomen above the hernia site. The surgeon pushes any protruding tissue back into the correct location, and stitches the incision closed. The downside is that there’s a high rate of recurrence.
- Tension-free repair: Now the most common repair method, mesh is used to bridge over the hernia defect - instead of sewing two sides of the hernia together.
- Laparoscopic tension-free repair: The surgeon makes 3-4 incisions in the abdominal wall, inserts a small tube, which allows instruments and a small video camera to pass through the tube. Mesh is also used to place over the weakened area. The hernia, in this case, is repaired behind the abdominal wall instead of being repaired on the outside of the abdominal wall such as in other cases.
The History of Hernia Mesh
Usher’s technique led to the popularizing of the Lichtenstein repair 30 years later in which flat mesh is placed on top of the defect and doesn’t put tension on the muscles (tension-free repair).
The benefits of mesh were just accepted without extensive research. However, complications led doctors to conduct several trials of evidence-based research. Although mesh was found to be superior to other techniques - with fewer cases of postoperative pain and recurrence - the theory behind mesh, the encouragement of scar tissue formation, has led to pain and movement restriction in some patients. To reduce this pain, mesh with lower surface area and more strength had to be created, which led to the creation of lightweight meshes.
Lightweight Mesh Development
First introduced in 1998 - as the product Vypro - lightweight meshes had large pores (3-5 mm) and a small surface area, reducing inflammatory reaction with greater elasticity and flexibility. With less shrinkage in the body, the repairs have resulted in decreased pain, but despite improvements, there are still complications such as recurrence, infection, and adhesion formation. The ideal mesh has yet to be created.
Composite Mesh Development
To find an “ideal” mesh, composite meshes were developed by combining more than one material. These are now the most common mesh design, containing three basic materials: polypropylene, polyester, and polytetrafluoroethylene (ePTFE). The advantage is they can be surgically placed through the thin tissues of the stomach and the intestines with minimal adhesion, but all literature points to disadvantages of using synthetic materials in the body.
Bio mesh is being developed where the matrix allows the soft tissues to grow in and around the mesh, but as it integrates with the body there’s a reduction in repair strength.
Complications of Using Mesh
The surgeon often decides what type of mesh the patient needs and which risks might occur. Materials containing ePTFE have a lower adhesion risk, but high risk of infection. Polypropylene meshes are durable with a low infection risk, but are inflexible and have a high adhesion risk.
Infection often occurs because of pore size. Large porous meshes have a higher risk of infection where blood cells (macrophages and neutrophils) enter into the pores allowing bacteria to survive within the pores. By contrast, smaller pores do not allow bacteria to remain in the pores (but they have risks too!).
When meshes adhere to the body, the body treats the site as trauma and inflammation occurs. Absorption is slower. Most meshes produce some level of adhesion, which encourages fibrosis (scar tissue formation). Meshes that have lower rates of adhesion aren’t as strong. Composite meshes allow cells to grow over the mesh, which is a good thing, but any adhesion and scar tissue can cause pain and reduce movement.
Meshes reduce the risk of chronic pain when compared to suture repair, but that’s often down to the tension-free technique and not the material itself. However, pain is often a symptom of mesh repair too - from scar tissue formation to infection, and other complications.
What’s the best mesh to use?
If you have to have a hernia repair, it’s best to use a lightweight mesh with large pores and a small surface area. With any surgery, and with injecting any foreign, non-organic material into the body, there can be complications. The most important factors are your surgeon's placement of the mesh when performing the repair; the mesh should not be too small for the area nor should the surgeon create unnecessary tension, which will undoubtedly cause complications - no matter the material used - and can cause hernia recurrence. Do be aware, however, that some meshes have been recalled from the market by the FDA and are not safe.
Does mesh do more harm than good?
The answer is complicated. Currently, there are no better methods. All types of repair come with their share of problems. As said before, with only mediocre options to choose from, the best you can do is choose a skilled, experienced surgeon who has performed hernia repairs with minimal complications in patients. A skilled surgeon can make all the difference in recovery.
Have you been harmed by the complications of composite mesh?
You could be eligible for compensation. At Coxwell & Associates we have a team of experienced personal injury lawyers who are ready to hear about your case. Find out more.
Disclaimer: This blog is intended as general information purposes only, and is not a substitute for legal advice. Anyone with a legal problem should consult a lawyer immediately.