UC San Diego

During transgastric natural orifice transluminal endoscopic surgery (NOTES), there is an iatrogenic perforation of the gastric wall with leakage of gastric contents into the peritoneal cavity. The aim of this study is to determine the effect of proton-pump inhibitors (PPI) and alterations of gastric pH on infection during transgastric surgery. Thirty 250-g male Sprague–Dawley rats were divided into a study group (SG, n = 15) and a control group (CG, n =15). SG were given 5 mg/kg pantoprazole for 3 days before procedure and another dose 1 h before. CG received saline at similar time points. A mini-laparotomy with gastrotomy was performed. Aspiration of 2.0 cc gastric contents was removed from the stomach and injected into the peritoneal cavity of both groups. Gastric pH and peritoneal pH levels were obtained. Gastric aspirate was sent for culture. White blood cell counts (WBC) were obtained on postoperative days 1, 7, and 14, and C-reactive protein (CRP) levels were obtained on postoperative day 1. At day 14, a necropsy was performed and aerobic and anaerobic cultures of the peritoneal cavity were obtained. There were no deaths in either group. The average gastric pH in the SG was 5.13 versus 3.26 (p = 0.03) in the CG. The average peritoneal pH was similar in both groups. The WBC in the SG was 4.5 vs. 3.5 (1,000 cells/mm) in the CG. There was no elevation in CRP levels in either group. Bacterial cultures were positive in 3/15 (20%) rats in the CG and in 9/15 (60%) in the SG (p = 0.008). Intra-abdominal abscesses were found in 2/15 (13%) rats in the CG and in 5/15 (33%) in the SG (p = 0.08). Pretreatment with a PPI resulted in a higher rate of peritoneal bacterial contamination and abscess formation. The acidic environment of the stomach appears to be protective against infection when intraperitoneal contamination occurs as a result of gastrotomy.