The Ten Year Window
I have spent many years in the health care industry. The outcome of the observations I have made tells me that most often it takes about 10 years for facts to catch up with drug, treatments, and device approvals.
Approvals in this arena come from the Food and Drug Administration (FDA). Commonly, because of the faster fast track system instituted now for a couple of decades, money buys the ticket to the train. When first instituted Fast Track cost a manufacturer about $330,000; now it is at least double.
This doesn’t end up doing too much for safety because, if you follow the news, you too frequently hear about a drug recall, an ineffective treatment, or medical device failures along with product liability law suits.
Surgical mesh offers no different scenario.
Retropubic urethral suspension was first used in 1910. Since that time over 100 different surgical techniques for the treatment of genuine stress urinary incontinence (GSUI) have been described.
Procedures done through the abdomen have been referred to as "bladder lifts". These include procedures known as the Burch repair and Marshall-Marchetti (1949) procedure. Although these are very "old" surgical procedures, the results have proven durable over time.
Some surgeons believe that the sling surgery should be used only in certain special cases because of its higher rate of complications and because they have found the older surgery techniques to be effective.
In instances where mesh may be contraindicated the procedures can be done with natural products such as bovine, or cadaver grafts.
Your physician should discuss all options with you for your situation to help you to decide which procedure is the correct one for you.
In the early 1990s, at the time use of surgical mesh began becoming popular there were no long term studies available on the differing types of products, and few long term studies of the surgical techniques.
Vaginal mesh repair has become popular, because of access to the areas involved in surgery, ease of application using the manufacturers' needles, variable mesh sizes that can be cut to size during surgery, laparotomy is not required, the option of achieving permanent tissue replacement after failure of tissue reconstruction, and experience with similar materials.
According to Dr. Saralyn Mark, a spokesperson for COOK in the capacity of Senior Scientific Policy Advisor, surgical mesh has been used for over a decade. COOK has provided biologically-derived grafts that are not cross-linked, including grafts for pelvic organ prolapse, for about 13 years. Dr. Mark’s statement was part of her presentation in September 2011 at the FDA conference covering the problems with this product.
There are several types of mesh or similar products and they are most often used in surgery involving hernia, uterine prolapse, bladder prolapse, rectocele, cystocele, and other applications.
Synthetic mesh is found in absorbable and non-absorbable forms. Biologically derived graft material is offered in cross-linked and non-crosslinked forms.
The type of material selected and the outcome of surgery is, according to Marks, best determined by “(1) assuring that the patient is a suitable candidate, (2) performing the procedure correctly, and (3) choosing the appropriate product”.
Based on the three criteria, Marks went on to state that she reviewed numerous articles where the studies referenced one of the four types of material for implant.
COOK’s findings show that most non-absorbable synthetic mesh is made of Type I polypropylene. Outcomes for this type material suggest that there is a strong bond with mesh and surrounding tissue encapsulation. In some cases the long term tissue response is more like a foreign body reactions that may include granulation tissue, limited neovascularization, eventual fibrosis, and encapsulation.
Foreign body reactions are similar to transplant surgeries where anti-rejection drugs are commonly prescribed in an effort to reduce risk of rejection.
Absorbable synthetic mesh can rapidly degrade and does not provide long term tissue support. For this reason this type of product is rarely used.
Cross-linked biologic grafts are made with chemical agents to bond or “cross-link” collagen fibers together in an effort to reduce degradation. The material seems not to support normal movement of body cells into the graft is significantly. Because of this inflammation occurs and over time leads to a foreign body reaction and encapsulation. The tissue response of chemically cross-linked graft material has been found to be very similar to the synthetic products.
Non-crosslinked biologic grafts are minimally processed to remove cells and leave no cross-linked collagen.
They offer both mechanical strength and a platform to promote “cellular infiltration, proliferation, and remodeling of the patient’s tissue”. Long term outcome with this type product aids repair and reinforcement as the graft is replaced by connective tissue and normal blood supply.
Review of 15 years of reports using different types of graft material evaluated these studies for incidence of “(1) erosion, (2) pain including dyspareunia, (3) graft-related infection, (4) persistence or recurrence of prolapse based on objective measures (such as the POP-Q score), and (5) symptomatic recurrence.”
Of these five parameters the final evaluation specifically looked at three objective measures for each type of material: (1) erosion, (2) infection, and (3) objective measurement of recurrence. Pain and other symptomatic complaints were excluded.
Overall findings with non-absorbable synthetic mesh products had a 10% erosion rate, while crosslinked biologics had 6.2% rate. Repairs with non-crosslinked biologic grafts had the lowest erosion rate at 1.2%.
Infection rates associated with material types were approximately 4.0%.
Of course and of great concern to patients are pain and other complaints, including but not limited to forced lifestyle change and quality of life concerns.
There is great consideration given to the need for follow-up sonography to evaluate the anterior and posterior mesh positions after prolapse surgery. Reported frequently is a considerable discrepancy between the implanted mesh size and its length measured after six weeks by postoperative ultrasound.
In consideration of economic cost, the recently reported direct cost of pelvic organ prolapse surgeries were between $1012 million and $1251 million dollars. Of this $494 million (49%) covered costs for vaginal hysterectomy; $279 million (28%) were costs for both cystocele and rectocele repair; and $135 million dollars (13%) were allocated for abdominal hysterectomy.
Physician services accounted for 29% ($298 million) of total costs, and hospitalization accounted for 71% ($714 million). Twenty-one percent of all reported pelvic organ prolapse operations included urinary incontinence procedures ($218 million). If all of the reported surgeries were reimbursed by non-Medicare sources, the annual estimated cost would increase by 52% to $1543 million.
Procedures using surgical mesh are permanent. There may be benefit in first understanding long term complications as these may include mesh erosion into the vagina, bladder or rectum; painful intercourse; infection or bleeding.
The FDA has received thousands of complaints about surgical mesh. Examples follow of manufacturer and complaints filed as of 2009 -
Manufacturer Product names and Number of MAUDE* reports
American Medical Systems SPARC 65
Bard Pelvicol, Pelvisoft 64, 1
Boston Scientific Scimed Prefyx PPS, Obtryx Curved Single, Obtryx Mesh Sling, Advantage Sling System, Prefyx System Mid U, Mesh Sling System23, 1, 62, 29, 23, 78
Caldera T-Sling 2
Ethicon Gynemesh PS (K013718) a/k/a/ Prolift Pelvic Floor, Prolene Polypropylene Mesh 123, 72
Gynecare Secur, Tension Free Vaginal Tape 1, 4
Johnson & Johnson – Switzerland K974098 495
Mentor ObTape (K031767) 236
Sofradim Uretex TO, Avaulta Biosynthetic, Uretex Pubovaginal Sling/support kit, Bard Posterior Biosynthetic Support System, Pelvetex Polypropylene Mesh 64, 0, 27, 3, 0
*MAUDE (Manufacturer and User Facility Device Experience) data represents reports of adverse events involving medical devices received by the FDA.
Cases involving Kugel Mesh Hernia Patches involving hernia repair are also on the increase. Davol, Inc., a division of the C. R. Bard, Inc., in December 2005 issued a recall following reports that the patch memory recoil ring may not withstand stresses associated with specific surgical placement techniques. The recall extended into 2006 and a law suit was filed against this product in December 2006.
Expanded recalls into 2007 were related to memory recoil ring breaks that had caused bowel perforation, bowel obstruction, internal pain, internal fistulas, migration through the abdominal wall, and additional surgery for repair or removal of mesh, blood clots, and death caused by septic shock. A case of acute heart attack secondary to surgery for bowel fistula repair was caused by perforation from the broken memory recoil ring.
Infertility has been reported secondary to a fibrotic reaction to mesh used in surgery for repair of inguinal hernia.
Some studies report that there can be a systemic allergic reaction to polypropylene mesh used in surgical treatment. These studies found too that Polytetrafluoroethylene (PTFE - fluoride) coated mesh, DuPont’s synthetic fluoropolymer of tetrafluoroethylene, may cause a greater risk.
Many researchers determined that skin patch tests should be conducted on patients in a timely manner before undergoing any surgery using polypropylene materials.
Davol and Bard were later involved in an FDA criminal investigation related to the sale of counterfeit surgical mesh kits containing flat sheets of polypropylene.
Between 2002 and 2006 Davol sold approximately 32,000 kits worldwide. In 2005 mesh kit sales generated $11 million for this firm.
In September 2011 the FDA called for the Obstetrics & Gynecology Devices Advisory Committee to discuss the issues related to the use of surgical mesh for treatment of pelvic organ prolapse (POP) and stress urinary incontinence (SUI).
The panel discussed the use of surgical mesh and its risks and benefits based on the literature and adverse reporting data (MAUDE).
Comments were taken about proposed FDA premarket and post market regulatory strategies for surgical mesh use in POP and SUI, and reclassification from Class II into Class III.
The goal of the panel is to assist FDA in determining whether there is need for additional clinical studies (premarket and/or post market) on surgical mesh use, based on data from the published literature and the MAUDE database.
Perhaps as we move in to the future more careful consideration will be given to evaluation based on other than journal articles and adverse reporting data.
This article is part of a consumer health education series written by Gayle Eversole, DHom, PhD, MH, NP, ND, of Creating Health Institute, in collaboration with Chaffin Luhana LLP
The views expressed in this article are solely those of the author, Gayle Eversole.