Development of an animal model to study meshes used in genital prolapse surgery.
OBJECTIVE
The objective was to develop an animal model using bacterial inoculation to evaluate tissue integration and tolerance to meshes used in genital prolapse surgery.


METHODS
We placed three different meshes under the abdominal skin of 120 Wistar rats: a polypropylene monofilament non-coated mesh (Parietene), a polypropylene monofilament collagen-coated mesh (Ugytex) and a polyethylene terephthalate mesh (Mersuture). We performed bacterial inoculation just after implantation with 1 ml of 10(7) colonies forming unit (CFU) of Staphylococcus epidermidis or Escherichia coli. Rats were sacrificed 7, 14, 60, and 90 days after intervention. We used polarised light microscopy to analyse the collagen deposition and organisation. We quantified the inflammation cells. Bacterial analysis and quantification of the explanted meshes were performed. The exact Fisher's test and Kruskal-Wallis test were used for statistics.


RESULTS
We did not find any significant difference between inoculated or non-inoculated meshes in terms of collagen deposition. The scarring process seemed stable at day 90. Tissue integration was best with the polypropylene meshes, which allowed the development of a well-organised, mature connective tissue. Inflammatory reaction was higher in inoculated meshes, but only at day 7. At day 90, we found a high number of macrophages and multinuclear cells around all the meshes. There was no significant difference between prostheses that had been inoculated and those that had not with regard to positive bacterial culture. Quantification of bacterial colonies decreased with time.


CONCLUSIONS
In this animal model, we did not find any clinically related difference in infection and tissue integration between the meshes used in genital prolapse. Such experimental studies must be carried out whenever new prostheses become available before their use is validated in common practice.
Boulanger
L
L
Department of Medical and Surgical Gynecology, Hôpital Jeanne de Flandres, Centre Hospitalier Régional Universitaire de Lille, 59037 Lille Cedex, France. l-boulanger@chru-lille.fr
Boukerrou
M
M
Rubod
C
C
Fruchart
A
A
Courcol
R J
RJ
Devos
P
P
Defossez
A
A
Cosson
M
M
D000818:Animals; D052858:Cystocele / Q000601:surgery; D004195:Disease Models, Animal; D004927:Escherichia coli Infections / Q000209:etiology; D005260:Female; D051381:Rats; D017208:Rats, Wistar / Q000601:surgery*; D013203:Staphylococcal Infections / Q000209:etiology; D013526:Surgical Mesh / Q000009:adverse effects*; D013530:Surgical Wound Infection / Q000382:microbiology; D013519:Urogenital Surgical Procedures / Q000009:adverse effects*; D014596:Uterine Prolapse / Q000601:surgery