title: Experimental study of inflammatory response and collagen morphometry with different types of meshes.
abstract: OBJECTIVE
  To compare an inflammation score and collagen morphometry after incisional hernia repair with four different meshes at two time points.
  
  
  METHODS
  Four types of mesh were used to repair an abdominal wall incisional defect in Wistar rats: high-density polypropylene (HW/PP); low-density polypropylene (LW/PP); polypropylene mesh encapsulated with polydioxanone coated with oxidized cellulose (PP/CE); and expanded polytetrafluoroethylene (ePTFE). An inflammation score based on histological analysis and collagen morphometry was performed after 7 and 28 days after operation (POD).
  
  
  RESULTS
  Compared to LW/PP group at 7 POD, HW/PP group had lower (p = 0.014) and PP/CE group had higher inflammation scores (p = 0.001). At 28 POD, higher scores were seen in all the other groups compared to the LW/PP group (HW/PP, p = 0.046; PP/CE, p < 0.001; ePTFE, p = 0.027). Comparing groups individually at 7 and 28 PODs, all demonstrated lower inflammation score values at 28 POD (HW/PP, p < 0.001; LW/PP, p < 0.001; PP/CE, p = 0.002; ePTFE, p = 0.001). At 7 POD, higher amounts of collagen were detected in ePTFE compared to HW/PP (p < 0.001) and LW/PP (p = 0.004) and in PPCE group compared to HW/PP (p = 0.022). At 28 POD, no statistically significant difference was found. Comparing groups individually at 7 and 28 PODs, HW/PP and LW/PP showed larger amounts of collagen at the 28th POD, without any statistically significant differences for the PP/CE and ePTFE groups.
  
  
  CONCLUSIONS
  Inflammation scores decreased in all groups at 28 POD. Collagen deposition was higher for non-composite meshes at 28 POD.
authors.affiliation: Interdisciplinary Surgical Science Post-Graduate Course, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil. carlosmaeda70@gmail.com.
authors.forename: C T
authors.initials: CT
authors.lastname: Maeda
authors.affiliation: Department of Pathology, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil.
authors.forename: R
authors.initials: R
authors.lastname: Artigani Neto
authors.affiliation: Interdisciplinary Surgical Science Post-Graduate Course, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil.|Division of Surgical Gastroenterology, Department of Surgery, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil.
authors.forename: G J
authors.initials: GJ
authors.lastname: Lopes-Filho
authors.affiliation: Interdisciplinary Surgical Science Post-Graduate Course, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil.|Division of Surgical Gastroenterology, Department of Surgery, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil.
authors.forename: M M
authors.initials: MM
authors.lastname: Linhares
mesh_terms: D000818:Animals; D003094:Collagen / Q000032:analysis / Q000737:chemistry* / Q000502:physiology; D004195:Disease Models, Animal; D006555:Hernia, Ventral / Q000503:physiopathology* / Q000601:surgery; D000069290:Incisional Hernia / Q000503:physiopathology* / Q000601:surgery; D007249:Inflammation / Q000503:physiopathology*; D008297:Male; D011108:Polymers / Q000009:adverse effects; D019919:Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation; D051381:Rats; D017208:Rats, Wistar; D013526:Surgical Mesh / Q000009:adverse effects*; D014945:Wound Healing / Q000502:physiology*
chemical_list: D011108:Polymers; D003094:Collagen
keywords: Collagen; Incisional hernia; Inflammation; Polypropylene