This article will summarize
findings by a review article published in the June, 2012 issue of Current Urology Reports Journal which
assesses outcomes and complications when synthetic mesh is used in the surgical
treatment of pelvic organ prolapse as well as FDA findings on the subject.
Pelvic organ prolapse occurs when the muscles and tissues which hold such
organs as the bladder, uretha, uterus and vagina in place break down, allowing
the organs to move downward. The location of the defect determines its
classification, including anterior (cystocele), posterior (rectocele) and
apical (enterocele).
Traditional pelvic organ prolapse
repair known as a colporrhaphy, either folds the native tissue or anchors them
to surrounding structures. 17% of the repairs which use these techniques will
require further surgical procedures. Grafts are used to strengthen weak
tissues, decreasing the likelihood of recurrence. Graft use also allows
surgeons to repair multiple sites in the same operation. Biologic grafts can
consist of autografts (tissue from the same individual) allografts (tissue from
another human) or xenografts (non-human organism tissue). Limitations to
biologic grafts include cost, limited availability and the risk of disease
transmission. Because of these limitations, synthetic mesh used in the repair
of POP was approved by the FDA in 2001.
Synthetic grafts are
classified according to filament number and pore size with variations in weight
and flexibility. Type 1 mesh is macroporous, monofilament polypropylene,
marketed under such brand names as Marlex™, Atrium™,
Prolene™, Gynemesh™ and Pelvitex™. Type 1 mesh appears to
have the highest rate of success due to its larger pore size which leads to
better tissue grown and lower rates of infection. Despite this success rate,
these vaginal mesh kits can provoke the body’s defense cell responses, causing
the formation of granulomas.
The specific surgical
technique used also has bearing on the rate of success in POP repair. Whether
anterior, posterior or apical, the traditional colporrhaphy procedure may be
implemented or the augmented procedure can be used. Regarding anterior repairs,
mesh augmentation decreased recurrence rates however showed higher rates of
complications. Apical compartment repairs also showed better results when mesh
augmentation was used however no significant differences were noted between
colporrhaphy and mesh augmented procedures when repairing the posterior
compartment.
Complications associated with
synthetic mesh kits are classified by the affected area, subdivided by time of
occurrence such as an immediate physician-caused injury, short-term erosion and
bleeding or long-term mesh extrusion, pain or painful sexual intercourse.
According to the data in this particular article, incidence of erosion and
extrusion range from 5-19%. Stress incontinence as a side effect of surgery
occurred less often in colporrhaphy procedures than those which used surgical
mesh. Painful sexual intercourse occurred equally in both groups, with the
exception of a higher rate in posterior compartment colporrhaphy repairs. One
study presented in the article noted that polypropylene meshes can retract up
to 66% following surgery, leading to vaginal shortening and narrowing.
The French Health Authorities
stated in 2006 that more research is required regarding the use of synthetic
mesh in POP repair. The FDA followed in 2008 by issuing a public health
notification regarding the use of synthetic mesh in POP repair. Suggestions
offered included specialized physician training as well as using mesh only
after weighing other alternatives. Physicians were advised to inform patients
of potential complications as well as to ensure they understand that the mesh
is considered permanent. An update to the 2008 notification was issued by the
FDA in 2011 which stated that complications from the use of mesh in POP repair
were “not rare” and that it was unclear whether the use of mesh showed any
benefit over traditional repairs. Literature in this article, however,
concluded that the FDA’s view was biased and that further research was
necessary to compare colporrhaphy to repair using synthetic mesh kits.
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