Differences in polypropylene shrinkage depending on mesh position in an experimental study.
BACKGROUND
Polypropylene (PP) mesh is one of the most frequent materials used in hernia repair. We have experimentally evaluated the shrinkage of PP mesh depending on the place of implantation.


METHODS
In 15 New Zealand rabbits a muscular defect measuring 3 x 3 cm was created in both pararectal sides of the abdominal wall. The defect was repaired using a PP mesh measuring 5 x 3.5 cm that was placed in the right side in the sublay location and in the left side in the onlay location. Five animals were killed on the 30th, 60th, and 90th postoperative days. Macroscopic measurement and microscopic study of the prosthesis-host tissue interfaces were performed.


RESULTS
One rabbit was killed because of severe infection in the onlay mesh. Another 2 infections were tolerated in the onlay mesh side. All the prostheses were integrated in the host tissue at death. In the macroscopic evaluation the mesh areas were reduced by 25.92% on the 30th day, by 28.67% on the 60th day, and by 29.02% on the 90th day. The mesh shrinkage was greater in the onlay group than in the sublay group at the 3 time intervals. More inflammatory leukocyte and mononuclear responses also were seen in the onlay group.


CONCLUSIONS
These observations support the theory of PP mesh shrinkage as a consequence of the incorporation of the biomaterial to the scarring tissue. This shrinkage is significantly more intense if the meshes are placed in the onlay position.
García-Ureña
Miguel Angel
MA
Department of Surgery, Cadiz University School of Medicine, Cra Nacional IV, Km 665, 11510 Puerto Real, Spain. mgarciau@meditex.es
Vega Ruiz
Vicente
V
Díaz Godoy
Antonio
A
Báez Perea
Jose María
JM
Marín Gómez
Luis Miguel
LM
Carnero Hernández
Francisco Javier
FJ
Velasco García
Miguel Angel
MA
D000818:Animals; D001672:Biocompatible Materials / Q000494:pharmacology*; D005260:Female; D046449:Hernia, Abdominal / Q000601:surgery*; D008422:Materials Testing; D011126:Polypropylenes / Q000494:pharmacology*; D011817:Rabbits; D013526:Surgical Mesh; D014945:Wound Healing
D001672:Biocompatible Materials; D011126:Polypropylenes