A BETTER MATERIAL FOR TREATING STRESS URINARY INCONTINENCE

A novel biocompatible material that mimics pelvic floor tissues to provide a safer treatment for stress urinary incontinence in women.

THE TROUBLE WITH POLYPROPYLENE MESHES FOR TREATING SUI

A recent publication from the University of Sheffield has identified some of the underlying issues surrounding the use of polypropylene meshes for treating stress urinary incontinence. The authors explain …

“How can a biomaterial that has worked very well in one site in the body - for the repair of abdominal hernias - not do as well when implanted to support the pelvic organs?

In the world of biomaterials, it's best not to make assumptions but rather to test as thoroughly as you can to determine whether a material will perform effectively and without side effects in the location you intend to implant it.

Controversy abounds over the use of polypropylene mesh, which has worked well in the abdomen but can cause sustained inflammation, fibrosis and even erosion of the material through a patient's tissues when implanted in the pelvic floor of women for treating stress urinary incontinence.

The forces experienced by implanted materials are very different when placed flat against the abdominal wall compared to holding up the soft, flexible tissues found in the pelvic floor. Tests in the laboratory do not apply mechanical forces to implanted materials and this can lead to potential problems being missed.

This study builds on previous work showing that polypropylene cannot withstand repeated and sustained stretching. So what happens when the surveillance squad of the immune system – the macrophages – encounters this stretched polypropylene material?

Macrophages are not activated by the basic polypropylene material. However, after polypropylene had been subjected to 72 hours of repeated distension and mild oxidative stress, a suite of sensitive analytical techniques detected changes to the surface of the material. Do these changes matter? This study definitively shows that macrophages now responded to this prestressed material with expressions of inflammatory and fibrotic genes. 

By applying appropriate forces and macrophages, and then detecting surface changes using sensitive analytical techniques, the described laboratory-based tests may be able to predict biomaterials that will not do well clinically.

The moral of the story is if you go looking for trouble you will find it. One cannot assume that a material that performs well in one site in the body will continue to do so when implanted in another site in which the mechanical forces are significantly different.”

Uncovering the relationship between macrophages and polypropylene surgical mesh ➡