title: Experimental study comparing the tensile strength of different surgical meshes following aponeurotic-muscle deformity synthesis on Wistar rats.
abstract: OBJECTIVE
  To assess the tensile strength of polypropylene and polypropylene associated with polyglactin meshes (Vypro II--Ethicon, Somerville, NJ, USA) in a situation of partial separation of abdominal muscle aponeurosis on rats.
  
  
  METHODS
  Thirty rats were used of the Wistar strain, which were randomized into two groups of 15 specimens each. In both groups an aponeurotic-muscle deformity was created on the abdominal wall measuring 3.0 x 1.0 cm, which was closed with polypropylene mesh (polypropylene group) or Vypro mesh (vypro group). After 28 days the rats underwent euthanasia and an area was removed from the abdominal wall with which a strip was made measuring 2.0 cm in length and 6.0 cm in width comprising the abdominal muscles with the implanted mesh. This sample was placed in a mechanical test machine in which a constant force was applied contrary to the tissue strips. Maximum force expressed in Newton was considered until full rupture of the sample occurred. The non-parametric Kruskal-Wallis test was used for statistical analysis admitting p< 0.05.
  
  
  RESULTS
  Out of the thirty animals, there were two deaths in the vypro group and one unit in the polypropylene group was lost. One animal in the polypropylene group developed hernia during the study and another one developed granuloma of the abdominal wall. All animals in both groups developed epiplon adherence to the mesh. The average force was 48.08 N for the polypropylene group and 45.32 for the vypro group.
  
  
  CONCLUSIONS
  In these experimental conditions it could be observed that there is no statistically significant difference in the rupture force of the polypropylene and Vypro meshes (p=0.54).
authors.affiliation: Santa Catarina South University, 88034-420 Florianópolis, Santa Catarina, Brazil.
authors.forename: Armando José
authors.initials: AJ
authors.lastname: d'Acampora
authors.forename: Darlan de Medeiros
authors.initials: Dde M
authors.lastname: Kestering
authors.forename: Marly da Silveira
authors.initials: Mda S
authors.lastname: Soldi
authors.forename: Lucas Félix
authors.initials: LF
authors.lastname: Rossi
mesh_terms: D000009:Abdominal Muscles / Q000601:surgery*; D000818:Animals; D004195:Disease Models, Animal; D008297:Male; D011098:Polyglactin 910 / Q000009:adverse effects*; D011126:Polypropylenes / Q000009:adverse effects*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D018709:Statistics, Nonparametric; D013526:Surgical Mesh / Q000009:adverse effects*; D013718:Tensile Strength; D000267:Tissue Adhesions
chemical_list: D011126:Polypropylenes; D011098:Polyglactin 910