Transgastric endoscopic pneumoperitoneum versus laparoscopy: effects on host systemic and peritoneal inflammatory responses in a porcine model

Abstract

The host systemic and peritoneal immune responses during natural orifice transluminal endoscopic surgery (NOTES) continues to be delineated. The immune response to laparoscopy (LAP) has been favorably depicted. However, the immunologic effects of NOTES are yet to be determined, and the introduction of contaminants via the host orificium may have deleterious effects. The purpose of this study was to characterize the effect that NOTES would have on porcine systemic and peritoneal immune function. Twenty-four pigs were divided into three groups: ENDO (upper-endoscopy control), NOTES, and LAP. All animals had blood and peritoneal lavage samples collected for cytokine analysis pre- and postoperatively. Interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-10 (IL-10), tumor necrosis factor α (TNFα), and interferon γ (IFNγ) levels were quantified using enzyme-linked immunosorbent assay (ELISA). Peritoneal lavage samples were cultured and identified by group and time of collection for microbiological analysis. TNFα was found in detectable levels in serum samples of all three groups. For the NOTES group, there was a significant increase in TNFα at t=1h (P<0.01), which dropped significantly at t=48h (P<0.01). IL-1β was present as an early response in NOTES lavage samples (t=0 and t=1h). Both LAP and NOTES had similar elevation of IL-1β in the final lavage samples at t=48h. The other cytokines were not consistently found above detectable levels in any group. Similar microbiological contaminants were found in the ENDO and LAP groups. In the NOTES group, no significant growth was observed from cultures at 48h. For measurable cytokines, the NOTES inflammatory response was not significantly different from that of the LAP group. NOTES did not carry a significantly increased amount of microbiological contamination at 48h compared to LAP. These data suggest that the host immune response to NOTES does not significantly differ from that to LAP in a porcine model.