Pulmonary and peritoneal inflammatory findings in transgastric NOTES compared with laparoscopy: Pooled analysis from randomized porcine survival studies

Background: Laparoscopy, which is a minimally invasive surgery, is associated with decreased peritoneal adhesions and inflammatory response compared with laparotomy. Objective: To evaluate whether natural orifice transluminal endoscopic surgery (NOTES) leads to an attenuated peritoneal response compared with laparoscopy. Design: Pooled histologic analysis from 2 randomized porcine trials. Setting: Laboratory. Intervention: Histologic analysis of swine undergoing diagnostic laparoscopy, diagnostic NOTES peritoneoscopy, NOTES with transgastric mesh placement, or diagnostic endoscopy (no gastrotomy) followed by laparoscopic mesh placement. Main Outcome Measurements: The presence and grade of inflammation in necropsy specimens of lung, liver, and spleen as reviewed by a blinded veterinary pathologist. Results: Four NOTES mesh animals exhibited mesh infections at necropsy. Tissue from 48 swine were available for analysis. Pulmonary inflammation, liver fibrosis, and spleen capsulitis were the primary findings. No difference was seen in the incidence of each finding among groups. The severity of the pulmonary inflammation in the laparoscopy group was significantly higher than in the NOTES groups. The NOTES mesh group exhibited significantly more severe liver fibrosis and spleen capsulitis. There was no difference between clinical behavior, serum white blood cell count, or peritoneal white blood cell count among groups in either study. Intra-abdominal pressures during NOTES were lower than during laparoscopy. Limitations: Pooled analysis of 2 separate studies. Conclusion: More severe pulmonary inflammation was found in animals undergoing longer laparoscopic procedures with higher intra-abdominal pressures. Intraperitoneal inflammation was most significant with transgastric mesh placement, likely caused by infections.