Transgastric versus laparoendoscopic single-site peritoneoscopy in a rat model: effects on motility, inflammation,...

Natural orifice translumenal endoscopic surgery (NOTES) and laparoendoscopic single-port surgery (LESS) are emerging approaches to abdominal surgery that have been advocated as potentially causing fewer physiologic derangements and less pain. This study aimed to compare these procedures in a novel rat model by assessing peritoneal inflammation, gastric motility, and nociception in response to peritoneoscopy performed via NOTES and LESS.

Adult male rats underwent peritoneoscopy via either transgastric NOTES or LESS using the same type of endoscope and were allowed to recover for 2 to 4 h. Liquid gastric emptying was assessed using phenol red, and cytokine levels were analyzed in peritoneal washings. Thoracic spinal cord segments were stained for Finkel-Biskins-Jinkins osteosarcoma gene (FOS) to assess activation of nociceptive pathways.

The NOTES procedure significantly delayed both postsurgical recovery time compared with LESS (115 ± 25 vs. 82 ± 20 min, respectively; P = 0.04) and liquid gastric emptying (26.7 ± 11.1% vs. 57 ± 10.5%; P = 0.004). Several cytokines such as interleukin-1β (IL-1β), IL-6, monocyte chemoattractant protein-1 (MCP-1), and macrophage inflammatory protein-1 beta (MIP-1β) were significantly elevated in the NOTES group compared with the LESS group. However, the two groups did not differ significantly in spinal FOS activation.

The NOTES approach is feasible in an experimental rat model, facilitating a scientific approach to hypothesis testing through specific methods and instruments. The transgastric NOTES approach in rats is associated with a worse physiologic outcome in terms of gastric motility and peritoneal inflammation but does not differ significantly from LESS in activation of pain pathways.