Medical Device Daily Contributing Writer

NEW ORLEANS — An FDA warning delivered last October, beginning with "This is to alert you to complications associated with transvaginal placement of mesh grafts for pelvic floor repairs," sent both gynecologists and mesh manufacturers hustling to address the issue.

Debates around this topic flourished in this newly rebuilt host city for last week's annual meeting of the Society of Gynecologic Surgeons (SGS; St. Louis). Many of the more than 300 SGS members attend this conference for its history of having top-notch academic surgeons in a very collegial atmosphere, as well as for addressing timely topics.

Conducted each year at this meeting is a survey on timely issues facing the female pelvic reconstructive surgeons present. Last year's survey results on the use of graft materials indicated that 71% of the respondents reported using either biologic or synthetic graft materials in vaginal reconstructive surgery, and that "Use of transvaginal graft material in pelvic reconstructive surgery in this subset of gynecologic surgeons is common."

The general feeling among the attendees was that the various meshes used for both stress urinary incontinence (SUI) as well as for pelvic organ prolapse (POP) repairs is safe and effective in the hands of experienced gynecologic surgeons. However, after the FDA issued its alert about mesh implants, patients began demanding surgery without mesh.

The fact is that without using mesh as a support, studies have shown that anywhere from 30% to 58% of the surgeries will fail over time; whereas only about 10% of those procedures that employed mesh may experience erosion, or exposure of the mesh through the vaginal wall.

Either using estrogen cream to stimulate tissue growth over the implant, or a simple procedure that retrieves the exposed mesh can treat the erosion; whereas with a failed surgery without mesh the patient must repeat the surgery. A presentation, "The Effect of Estrogen Replacement on the Histological Response to Polypropylene Mesh Implanted in the Rabbit Vagina", by E.W. Higgins, MD, of the Department of Female Pelvic Medicine and Reconstructive Surgery at Scott & White Hospital (Temple, Texas), demonstrated that "Estrogen replacement administered for eight weeks postoperatively increases collagen deposition into polypropylene mesh implanted in the rabbit vagina."

Although this appears to be an easily remedied problem, the dilemma for the surgeon becomes one of properly counseling those patients who feel that mesh may be harmful. To help guide practitioners in their decision to use or not use mesh, the Systematic Review Group of the SGS performed a systematic review of graft use in vaginal prolapse repair. All papers that included reports of graft erosion and were published between 1950 and 2007 were analyzed.

Graft erosion defined as graft material exposed in the vagina following surgery was documented in 46 papers with a mean weighted average erosion rate of 8.3%. The erosions occurred anywhere from 6 to 12 weeks following surgery. Their conclusion was that "graft erosion occurred in approximately 8% of women undergoing vaginal repair of pelvic organ prolapse with graft materials and that the wide variation in the reporting of adverse events makes concrete conclusions regarding the risks in its use difficult."

Two other presentations confirmed high successful surgery vs. mesh erosion rates. B.I. Kudish, MD, of the female pelvic health and reconstructive surgery unit at Georgetown University (Washington), opened by saying, "Although 86%-95% success rates have been published using polypropylene mesh, we wanted to assess the long-term success and quality-of-life outcomes when using polypropylene mesh in vaginal prolapse repair."

After following 62 patients for 20 months, she said, "the prolapse stage and quality of life were significantly improved in patients undergoing vaginal prolapse repair using synthetic polypropylene mesh. Concern for delayed mesh erosion exits." She also found that the anatomic success was lower than predicted but for the most part, the patients seemed pleased with their outcomes. They found a 9.8% mesh erosion rate.

Adam Holzberg, MD, of Cooper University Hospital (Voorhees, New Jersey), authored a poster, "Two Year Outcome Data of Efficacy and Quality of Life Following Mesh Augmented Vaginal Reconstruction," where he followed 38 patients for two years and found only one mesh erosion.

His conclusions were "There was overall improvement in quality of life and outcome following mesh augmented vaginal reconstruction. Most patients stated they would have the procedure again and would recommend it to a friend."

Several studies were presented here with the objective of better understanding mesh-associated problems and comparing the various synthetic meshes in regards to erosion rates.

P.S. Finamore, MD, female pelvic medicine and reconstructive surgery, Cooper University Hospital (Camden, New Jersey), gave an oral poster presentation "Erosion Rates Three Months Following Mesh Augmented Vaginal Reconstructive Surgery" where the meshes from Ethicon (Somerville, New Jersey) and Bard Urologic Division (Covington, Georgia) were compared as well as their associated kits that integrated each mesh.

"There was no difference in the erosion rates when combining and comparing the products from company 1 and company 2 (10% vs. 12%)," Finamore said, adding that there was a significantly lower erosion rate in the "kits" when compared to traditional repairs using the same free mesh.

In addition to clinical comparisons being presented by gynecologists, manufacturers have improved their mesh products with the objective of lowering the erosion rate while maintaining the high surgical success rate.

Ethicon, Boston Scientific (Natick, Massachusetts) and American Medical Systems (AMS; Minnetonka, Minnesota) have significantly reduced the amount of graft material placed. C.R. Bard, Ethicon and AMS offer resorbable, hybrid, or biologic grafts. Mpathy Medical (Raynham, Massachusetts) has created an ultralight macroporous version of former meshes. Table 1 highlights some of the newer approaches.

Mpathy, whose U.S. product launched after the FDA warning claims that its mesh products were developed specifically for female anatomy. Stephen Young, MD, chief of the Division of Urogynecology and professor of obstetrics and gynecology at UMass Memorial Medical Center (Worcester), discussed his experience using Mpathy's smartmesh at a sponsored dinner. He said that "non-resorbable synthetic grafts may improve anatomic outcomes, but there are trade-offs. Previous meshes yielded improved cure rates but had local complications because they were too stiff and thick to retain the elasticity of the vagina. We need a material that disappears when inserted: the silent mesh."

Jim Radars, MD, a urogynecologist from Minneapolis and a thought leader in this field, said, "Erosion is not our enemy. Many patients never complain and probably aren't even aware that they have mesh exposure. Pain is our enemy and that can be caused by many factors, mesh only being one of them."

Fecal incontinence: the silent suffering

Having your first morning coffee and a bagel at 6:30am along with a discussion on fecal incontinence hardly seems civilized until Dee Fenner, MD, of the department of obstetrics/gynecology at University of Michigan Hospital (Ann Arbor), explains the exciting new treatments soon to be available for these patients who are silently suffering a condition that has little resolution to offer them. From 3% to 15% of Americans, mostly women, experience involuntary solid, liquid, or gas leakage and doctors have little to offer them outside of dietary control and physical therapy.

"Fecal incontinence is not well understood and is very complicated," she said. "It can be a combination of neurosensory and anatomic defects caused by aging, childbirth, denervation, trauma – any number or combination of factors." For those patients who have tried and failed all other palliative therapies, surgery is an option, but without high expectations. "For patients who go on to have a sphincteroplasty, 75% will still have some incontinence, 15% will have flatus, and only 10% will be continent," Fenner shared, "Any improvement is greatly appreciated."

Two new therapies are almost ready for prime time and offer great hope for these patients. Medtronic's (Minneapolis) Interstim therapy product that has been used on over 50,000 patients worldwide for treatment of overactive bladder has been in clinical trials for fecal incontinence and is expected to be FDA cleared soon. Interstim, often referred to as the pacemaker for the bladder, consists of an implanted generator with leads attached to the sacral nerves that supply a mild electrical pulse.

The clinical trial underway is to determine if the same therapy will help with fecal incontinence. According to Fenner, "In places where the Interstim is being studied for fecal incontinence in Europe, virtually no sphincteroplasties are being performed any longer." From what she has heard, the data is compelling and Interstim implants should virtually replace both sphincteroplasties as well as artificial sphincter placements, a surgery that is associated with a 75% major complication rate.

Another exciting treatment for fecal incontinence is being developed by American Medical Systems and was conceived by Peter Rosenblatt, MD, director of urogynecology at Mount Auburn Hospital (Cambridge, Massachusetts) and current program chairman of SGS.

Called the TOPAS, for Transobturator Post Anal Sling, it is a sling that recreates the normal angle between the anus and the rectum, which helps women remain continent of stool. Since January 2006, more than 50 patients have been implanted, with a 70% success rate and no evidence of mesh erosion. These two new therapies could completely change the lives of millions of people.

No Comments