To avoid intestinal contamination of the peritoneal cavity is a long held surgical principle that is not fully compatible with Natural Orifice Surgery. We investigated the impact of gastric saline irrigation on bacterial content in animals pretreated with Proton pump inhibitors and in animals undergoing transgastric intraperitoneal mesh placement.
Methods: 24Yorkshire swine were randomized to NOTES transgastric mesh placement or proton pump inhibitor pretreatment for 14 days, upper endoscopy + laparoscopic mesh placement. A 12 swine control group received NOTES with diagnostic peritoneoscopy. All groups received prophylactic parenteral antibiotics and gastric lavage with 500 cc saline. Gastric aspirates were cultured on blood agar for 48 hrs. The laparoscopy group utilized a 3 trocar procedure with polypropylene mesh. In the NOTES mesh group a transport balloon was used to transfer the mesh into the peritoneal cavity under minimal contamination. In both groups the mesh was clipped to the periumbilical peritoneum. Total procedure time for all groups was preset at 90 minutes. The animals were survived for 14 days. At necropsy peritoneal and mesh infection was assessed.
Results: Gastric irrigation reduced bacterial content in the gastric aspirate significantly in all groups (p< 0.001). There was no statistically significant difference in the mean bacterial count after irrigation at 24 or 48 hrs between the group that had undergone PPI treatment and the untreated groups. In the endoscopy + laparoscopic mesh placement group no clinically apparent mesh infection was encountered. In the transgastric mesh placement group 4 of 12 animals were found to have a grossly apparent mesh infection (p= 0.03). In the infected group mean count of colony forming units at 24 hrs was 6.3 + 7.2; the bacterial count in the uninfected group was 6.9 + 9.1 (p=0.81). No peritoneal infection was seen in the NOTES control group.
Conclusion: Gastric irrigation with 500 cc saline significantly decreased the gastric bacterial count independently of pretreatment with proton pump inhibitors. Mesh infection was significantly more frequent in the transgastric route despite prophylactic antibiotics, gastric irrigation and a protective transport balloon. NOTES mesh infection appeared independent of the gastric bacterial count after irrigation in this study. Additional measures will have to be taken to enable translumenal mesh placement.