title: Effect of transgastric peritoneal access on peritoneal innate cellular immunity: experimental study in swine.
abstract: BACKGROUND
  One of the main concerns of natural orifice surgery is the local and systemic impact on physiology. Few studies have compared natural orifice transluminal endoscopic surgery (NOTES) with other surgical modalities. Most studies are based on systemic variables such as postoperative serum cytokines, with conflicting results. Surgical trauma induces an early inflammatory response, release of cytokines, and local leukocyte activation and oxidative burst. Major surgical trauma is related to impairment of phagocytic function and an increase in production of active oxygen species by phagocytes. The aim of this study was to evaluate the impact of transgastric peritoneoscopy on peritoneal innate immune response compared with laparoscopy and laparotomy in swine.
  
  
  METHODS
  Thirty-four male Sus scrofa domesticus swine were assigned to four groups: transgastric peritoneoscopy (13), laparoscopy (7), laparotomy (7), and sham procedure (7). Twenty-four hours after the procedure, peritoneal fluid cells were harvested by peritoneal washing after necropsy. Flow cytometry analysis of labeled S. aureus and E. coli phagocytosis by peritoneal neutrophils and macrophages was blindly performed. Oxidative burst activity measured by H(2)O(2) production under different challenges was also evaluated.
  
  
  RESULTS
  Total operative time varied between all groups. The transgastric, laparoscopy, and laparotomy groups required 56, 17.2, and 40.3 min of mean operative time, respectively (p < 0.05). Even though the mean percentage and intensity of phagocytosis by peritoneal phagocytes were higher in the sham, transgastric, and laparoscopy groups, there was no significant difference between these groups and laparotomy. Macrophage production of H(2)O(2) has been shown to be similar among the transgastric, laparoscopy, and sham groups, and smaller than that in laparotomy (p < 0.05), either under basal conditions, while performing E. coli phagocytosis, or challenged by the presence of E. coli membrane lipopolysaccharide.
  
  
  CONCLUSIONS
  Under the conditions of this study, transgastric peritoneoscopy has been shown to have minimal impact on peritoneal innate immune response.
authors.affiliation: Clinical Gastroenterology Division, Department of Medicine, São Paulo Federal University, São Paulo, Brazil, rodrigo.ar@terra.com.br.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Rodrigues
authors.forename: Marcelo
authors.initials: M
authors.lastname: Rezende
authors.forename: Gustavo
authors.initials: G
authors.lastname: Gomes
authors.forename: Fernando
authors.initials: F
authors.lastname: Souza
authors.forename: Maiara
authors.initials: M
authors.lastname: Blagitz
authors.forename: Alice Della
authors.initials: AD
authors.lastname: Libera
authors.forename: Murched
authors.initials: M
authors.lastname: Taha
authors.forename: Angelo
authors.initials: A
authors.lastname: Ferrari
authors.forename: Ermelindo Della
authors.initials: ED
authors.lastname: Libera
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D005609:Free Radicals / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D007111:Immunity, Cellular / Q000502:physiology*; D007113:Immunity, Innate / Q000502:physiology*; D010535:Laparoscopy / Q000379:methods*; D017737:Macrophages, Peritoneal / Q000378:metabolism; D008297:Male; D057605:Natural Orifice Endoscopic Surgery / Q000379:methods*; D009504:Neutrophils / Q000378:metabolism; D061646:Operative Time; D010537:Peritoneum / Q000276:immunology* / Q000601:surgery; D010586:Phagocytes / Q000276:immunology; D010587:Phagocytosis / Q000276:immunology; D034421:Sus scrofa
chemical_list: D005609:Free Radicals; D006861:Hydrogen Peroxide