Su1591 Effect of Transgastric Peritoneal Access on the Peritoneal Innate Cellular Immunity: Experimental Study in Swines

Aside from several technical issues limiting NOTES, one of the largest concerns to natural orifice surgery is the local and systemic impact on physiology. Few studies evaluated the physiologic impact of NOTES compared with other surgical modalities. Most of them are based on systemic variables such as postoperative serum cytokines, with conflicting results. Surgical trauma induces an early inflammatory response characterized by citokines release and local neutrophil/macrophage activation and oxidative burst. Major surgical trauma is related to impairement of phagocytic function and increasing of production of active oxygen species by phagocytes. To evaluate the impact of transgastric peritoneoscopy on the peritoneal innate immune response, compared with laparoscopy and laparotomy in swines. For this study, 34 male Sus scrofa domesticus swines were assigned to four groups: transgastric peritoneoscopy (NOTES, n= 13), laparoscopy (LX, n=7), laparotomy (OPEN, n=7), and sham procedure (CONTROL, n=7). Twenty-four hours after the procedure, peritoneal fluid cells were harvested by peritoneal washing after necropsy. Flow cytometric analysis of phagocytosis of labeled S. aureus and E. coli by peritoneal neutrophils and macrophages was blindly performed. Oxidative burst activity measured by H2O2 production under different challenges was also evaluated. Total operative time varied between all groups. NOTES, LX and OPEN groups required 56 (10,2), 17,2 (4,7) and 40,3 (10,7) minutes of mean operative time, respectively (P<0,05). Even though the mean values of percentage and intensity of phagocytosis by peritoneal phagocytes were higher in the groups CONTROL, NOTES and LX, there was no significant difference between these groups and group OPEN. The macrophage production of H2O2 has shown to be similar between the groups NOTES, LX and CONTROL, and smaller than group OPEN (P<0,05), either under basal conditions, while performing phagocytosis of E. coli, or challenged by the presence of E. coli membrane lipopolysaccharide. Under the conditions of the present study, diagnostic transgastric peritoneoscopy has shown to promote minimal impact on the peritoneal innate immune response.