|
Hot
Seat
"To Mesh" or
"Not To Mesh"
R. Edward Varner, MD
In recent years, several new procedures utilizing graft material to replace/augment “poor” paravaginal
(pubocervical and pararectal) connective tissue have been advocated for patients
with significant pelvic organ prolapse. These grafts are placed in the vesico-vaginal
space and recto-vaginal space and are anchored bilaterally to or through the
lateral pelvic walls (anterior to the arcus tendineus, and posterior to the
levator musculature) thereby recreating a “normal” posterior vaginal
axis. Potentially, grafts can allow an effective transvaginal approach for the
patient who has “very poor tissue” that could otherwise be repaired
only with a vaginal narrowing or obliterative procedure or by a combined abdominal/vaginal
procedure.
Biological grafts have been advocated by many surgeons. However, efficacy studies,
most with follow-up of <2 years, show mixed results and most reports that
indicate good results with procedures utilizing biologic graft materials have
not been confirmed by subsequent reports. All allograft and xenograft materials
resorb with time; therefore, the long-term strength of the repair is dependent
on the ability of the host’s connective tissues to maintain strength after
being incorporated into or encapsulated around the graft.
Observational studies of various synthetic meshes used for abdominal hernia
repairs, sacrocolpopexy procedures, midurethral slings and, now, paravaginal
procedures, indicate that low density monofilamentous polypropylene meshes with
pores >75 µ in diameter have infection and erosion rates much lower
than do high density meshes and those with multiple filaments, woven together.
With the advent of several surgical “kits” utilizing such a mesh,
there are now short-term follow-up reports (most not peer-reviewed) indicating
that such procedures yield anatomical success (Pelvic Organ Prolapse Quantification
scores <stage II prolapse) in >89% of subjects. These procedures do show
mesh erosion in approximately 3% to 15% of the subjects. However, these erosions
are, for the most part, exposures of the mesh without obvious infection. The
majority of these erosions have been managed by removal of visible mesh, which
is not incorporated into the host’s tissue, followed by closure of the
defect.
Recently, 248 patients undergoing surgery with one of the commercially available “kit
procedures” were evaluated for perioperative complications using a standardized
protocol.2 Of the serious
adverse events (4.4%), there was one case of bleeding in excess of 1000 cc,
and 10 visceral injuries (4 rectal, 5 bladder, and 1 urethral).
Longer term reported complications have included mesh erosion into the bladder
and rectum, development of fistulas, “band” formation in the vagina
and bladder, and rectal dysfunction. Not specifically reported are the (probably
rare) cases whereby areas of fibrosis develop in the vagina that may actually
cause agglutination and apareunia. Chronic pain may also develop in the area
of the mesh. Overall, these severe adverse effects appear to be rare, but many “specialist
surgeons” at referral centers, including myself, have seen such patients
somewhat frequently.
Theoretically, such problems may be reduced by:
- techniques to avoid tension on the graft material
- the avoidance of devascularization of the paravaginal tissue during dissection
- making sure that the graft is placed flat in the space to avoid bunching up,
and
- by pre- and postoperative optimization of the vaginal tissue including treatment
of atrophy and vaginitis when present. The effectiveness of these measures has
not yet been demonstrated.
Reports on series of patients with prolapse managed with traditional procedures
(transvaginal repairs with sacrospinous suspensions or high uterosacral suspension
and sacrocolpopexy with and without other repairs) have typically shown success
rates for the apical part of the suspension to be generally >85%. Overall
success has been somewhat less, with subsequent stage II or greater anterior
or posterior defects ranging from 11% to 50%. Thus far, anatomical successes
with these approaches are considerably less than those reported with mesh procedures.
However, interestingly, patient satisfaction with traditional procedures has
been good and quality of life scores improve even in the patients in which stage
II descent developed after surgery.
With the exception of mesh erosions, the adverse events which have occurred
with mesh procedures have also occurred with the more traditional procedures
and likewise have probably been under reported. However, anecdotally, it is
my perception that a greater number of patients have been referred to me with
vaginal agglutination, dyspareunia, and chronic pelvic pain since vaginal mesh
procedures have become common practice.
An appropriately designed randomized trial would answer the question of whether
mesh procedures have better benefit/risk ratios than do traditional procedures.
However, considerable time and expense would be required for such a trial to
be adequately powered. The design of such a trial would be fraught with difficulty
since no one traditional procedure is universally considered “gold standard” and
there is no agreement as to which “mesh procedure” is best, especially,
since new techniques and new meshes are evolving. The involvement of industry
in the development and competitive marketing of meshes and other surgical products
has hastened this evolution and may confuse surgeons trying to decide which
product is best.
At this time there is not enough evidence to determine the long-term benefit/risk
ratio for transvaginal “mesh” procedures. Available data indicate
that mesh procedures may produce anatomical success rates higher than do traditional
procedures when performed by surgeons who are experienced in these and other
procedures for prolapse. However, based on the data we have and anecdotal reports,
the incidence of serious adverse effects may be higher with mesh procedures.
It is my opinion at the present time that these procedures should be performed
only on patients desirous of subsequent sexual function (ie, a reconstructive
procedure), and those who have a relatively high risk for developing recurrent
prolapse after traditional procedures. Patients should be made aware of the
potential complications and adverse effects and given options. Surgeons not
experienced in prolapse surgery should not be performing it.
back to top
R. Edward Varner, MD, is Professor;
Division of Medical and Surgical Gynecology, and Director of the Fellowship
in Female Pelvic Medicine and Reconstructive Surgery, University of Alabama
at Birmingham Medical Center, Birmingham, AL.
References
- Richter HE, Varner RE. Pelvic Organ
Prolapse.
In: Bereck JS, ed. Bereck and Novak's, Gynecology. 14th ed. Baltimore:
Lippincott, Williams, & Wilkins; 2006:897-934.
- Altman D, Falcover C. Perioperative
Morbidity Using Transvaginal Mesh in Pelvic Organ Prolapse
Repair. Obstet Gynecol. 2007;109(2): 303-308.
- ACOG Committee on Practice Bulletins — Gynecology.
ACOG Practice Bulletin No. 85: Pelvic organ prolapse. Obstet
Gynecol. 2007;110(3):717-729.
|
