Is a better mesh on the way for women who suffer from pelvic organ prolapse and stress urinary incontinence?
Scientists at the University of Sheffield in England are on a mission to find a more suitable material for the vaginal mesh that is surgically implanted in women who live with these conditions.
They say polyurethane, a material used in insulation, mattresses, and other household items, may be that better option.
Currently, most vaginal mesh is made with polypropylene, a material used to make food containers, outdoor carpets, and other household items.
The Sheffield scientists say polyurethane mesh has more elasticity than polypropylene.
In addition, the researchers inserted estrogen into the mesh to help speed up the healing process.
In their research, the scientists said they found that the estrogen did not compromise the strength and elasticity of the mesh.
The researchers believe that polyurethane mesh with estrogen could help women avoid life-altering complications.
Pelvic organ prolapse and stress urinary incontinence are conditions that affect many women, including half of those who’ve reached menopause.
Treatment often involves surgery and use of transvaginal mesh.
The mesh is intended to provide support for pelvic organs.
But for some women, it ends up causing debilitating complications. These include persistent pain, inability to have sex, and organ perforation.
Severe complications occur more often when mesh is used for pelvic organ prolapse than for stress urinary incontinence.
“For many years now, surgeons have been treating the problems of urinary stress incontinence and pelvic organ prolapse using the only synthetic material they had on hand — polypropylene,” Sheila MacNeil, PhD, professor of tissue engineering in the department of materials science and engineering at the University of Sheffield, said in a press release.
“However, when much bigger areas of the same material are inserted through the vagina to relieve pelvic organ prolapse, the complication rate is frankly unacceptable,” she said.
In the United States, several makers of polypropylene meshes have faced lawsuits over complications.
As a result, they no longer market mesh for pelvic organ prolapse. The mesh is still marketed to treat stress urinary incontinence. When used for this purpose, the complication rate is low.
The new mesh still needs to undergo clinical trials in the United Kingdom.
Experts told Healthline that clinical trials in the United States are complicated and could take many years.
They note that the estrogen component adds an additional level of scrutiny. This is due to the risks of hormone use and potential risk of breast cancer, uterine cancer, stroke, heart attack, and blood clots.
Why surgeons use transvaginal mesh
“For many women, having children is a joy. But for those same women, years later, the effect of delivering babies, particularly if they are large babies, exerts a toll on the supporting structures of the female pelvis,” said Dr. Kecia Gaither, a double board-certified physician in OB-GYN and maternal fetal medicine and director of perinatal services at NYC Health and Hospitals System in New York.
Gaither told Healthline that menopause and hysterectomy can also be contributing factors.
“The vagina, bladder, or rectum may begin to sag, or prolapse through the weakened pelvic musculature,” she said.
Women experience such symptoms as sexual problems, urinary incontinence, and problems with defecation.
One remedy is surgery with the transvaginal mesh consisting of polypropylene.
“It is non-absorbable and most of the mesh made are of this type. There are meshes made of absorbable synthetic materials, whereby it’s absorbed within the body, and tissue grows over the mesh. There are others made of natural products derived from animals like the cow and pig. Lastly, there exist mesh made of a composite of non-absorbable synthetic plus absorbable synthetic or biologically derived,” explained Gaither.
“It’s used to essentially provide a supportive bridge to the sagging, weakened pelvic musculature,” she said.
Side effects and complications
“Some of the more common side effects of the surgical placement of this mesh include infection, erosion of the vaginal tissues, organ perforation, bleeding, neuromuscular dysfunction, and pain, particularly with intercourse,” said Gaither.
Treatment for complications could include vaginal estrogen therapy or revision surgery.
Dr. Michael Ingber is board certified in urology and female pelvic medicine and reconstructive surgery at The Center for Specialized Women’s Health, a division of Garden State Urology in New Jersey.
Ingber told Healthline that he does this type of surgery every week. He notes that there are different mesh procedures that have different complication rates.
“For example, suburethral slings have a very low complication rate and have been around since the 1980s. They are considered our gold standard therapy to treat stress urinary incontinence. The latest type of sling I tend to use is our mini-sling (Altis, Coloplast Corp). This sling has a 3 percent risk of a mesh exposure — where the incision doesn’t completely heal — over the sling mesh,” explained Ingber.
When that happens, a topical estrogen can be used to promote healing.
“However, in some cases, patients require the exposed mesh to be trimmed or removed. Because the sling is only 11 millimeters (mm) wide, this therapy is easy and can often be done even in the office setting,” he continued.
“One of the first mesh-related complications I saw was a 45-year-old woman who had her polypropylene mesh placed so tense by another surgeon that she had immediate pain right after the surgery. She hadn’t been able to have sexual relations with her husband for several years. After I removed the mesh and released some of the tension, in conjunction with intensive pelvic floor physical therapy, she was able to resume normal relations,” Ingber recalled.
“I currently use the Restorelle mesh from Coloplast. This mesh is one of the lighter-weight meshes on the market and is involved in the FDA postmarket surveillance studies. I have done several hundred vaginal mesh implants and the vast majority have done well. I have only two ‘failures’ so far with the vaginal mesh implants, where the mesh didn’t hold up well. The patients needed additional surgery to fix their prolapse,” said Ingber.
In the United States, the Food and Drug Administration (FDA) changed the classification of mesh for transvaginal repair of pelvic organ prolapse from moderate risk to high risk. This does not apply when the mesh is used to treat stress urinary incontinence.
Ingber is an investigator with Coloplast’s DirectFix mesh product.
“The FDA now requires any mesh manufacturers to undergo rigorous testing, and several studies are under way to evaluate women who have chosen this mesh product for prolapse, as opposed to a native tissue repair, or using dissolvable sutures to lift the bladder/uterus/rectum,” he said.
“The first thing we learned is that these products may not be appropriate for young, sexually active women with vaginal prolapse. These women tend to be at higher risk for pelvic pain and dyspareunia (painful sex). For women with a mild prolapse, a native tissue repair may be more appropriate. We learned that putting in these meshes requires expert technique and training so it isn’t placed too superficial in the tissue,” explained Ingber.
Ingber tells patients that his exposure rate is about 5 to 10 percent in vaginal mesh cases.
“However, it is important to note that even in these cases, because I typically choose nonsexually active, older women for these procedures, most of them are asymptomatic,” he said.
Potential of the new mesh material
“Women will have an exciting new option that confers less of a risk of complications, theoretically, than mesh made of polypropylene,” said Gaither.
She believes the addition of estrogen, particularly in postmenopausal women, is logical.
One drawback she sees is knowing what dose would be beneficial. She also notes the need to learn if this treatment would be inadvisable for women who have had estrogen-dependent cancers.
Ingber says doctors are always learning.
“We know now that polypropylene mesh has to be macroporous, or have large pores to allow collagen and tissue ingrowth. We also learned that lighter weight meshes, although out of the body seem weaker, are in fact stronger than heavier meshes once placed into the body,” he said.
According to Ingber, the gold standard repair for apical vaginal prolapse is sacral colpopexy (a surgical procedure). It can be performed with robotic-assisted, minimally invasive technology. The polypropylene “Y-mesh” is inserted abdominally.
“This carries a significantly lower risk than the transvaginally placed meshes, specifically related to exposure of the mesh, painful sex, and pelvic pain. We use this as a standard in younger, sexually active women with prolapse. I am not sure if we would get better results with a polyurethane Y-mesh,” said Ingber.
“With suburethral slings, a more elastic sling (which is what polyurethane appears to be) may be less desirable, as the more rigid support from polypropylene may provide the better hammock of support when women have stress urinary incontinence (leakage with coughing/sneezing),” he explained.
“I’ve read the studies on polyurethane slings. The ability of this sling to retain its nature is appealing. The more elasticity shown in vivo after implantation is appealing if we have to implant a large sheet of the mesh for prolapse repairs,” said Ingber.
Gaither advises women to consult with their doctors about their health history and potential side effects of all treatment choices.