Effectivity of current sterility methods for transgastric NOTES procedures: results of a randomized porcine study

Natural-orifice transluminal endoscopic surgery (NOTES) is an emerging transluminal technique in which interventions are carried out by entering the abdominal cavity via a natural orifice such as the stomach. Infection is a potential risk of the procedure, and the potential pathogens are different from those encountered with skin incisions. Currently, available data regarding prophylactic anti-infective treatment are limited. We compared the effectiveness of topical antimicrobial lavage of mouth and stomach and proton pump inhibitor therapy with gastric cleansing with sterile saline solution in preventing NOTES-related contamination and infection.

A randomized survival swine study was performed. Eight pigs underwent preparation with intravenously administered proton pump inhibitors, mouth and gastric lavage (chlorhexidine), and gastric irrigation (diluted neomycin), plus single-shot intravenous antibiotics. Control group (n = 8) underwent gastric cleansing with sterile saline solution. Peritoneal biopsy, multiple smears, and dilutions for cultures were taken and incubated. The swine were sacrificed after 14 days. Bacterial load was expressed in colony-forming units (CFU).

One pig died due to gallbladder perforation after 3 days, 2/15 swine presented minor clinical signs of infection in the 14-day follow-up (all 3 pigs were in the control group). Mean C-reactive protein levels were 5.7 +/- 2.4 g/dL (therapy group) and 12.2 +/- 3.8 g/dL (control) ( P = 0.17). Bacterial growth was seen in 1/8 swine (therapy group) and 6/8 swine (control group) ( P = 0.002). Bacterial load was 282 CFU/mL (therapy) vs. 3.2 x 10 (5) CFU/mL (control) ( P = 0.023) in the follow-up.

The use of intravenous antibiotics in addition to topical antimicrobial lavage of mouth and stomach and treatment with proton pump inhibitors decreased the peritoneal bacterial load to almost zero and this was associated with a significantly lower peritoneal infection rate compared with saline-only lavage.