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

Aims: Natural orifice translumenal endoscopic surgery (NOTES) is an emerging transluminal technique through which interventions are performed by entering the abdominal cavity through a natural orifice such as the stomach. Infection is a potential risk of the procedure and the potential pathogens are different than with skin incisions. Currently, there is limited data regarding prophylactic treatment with antibiotics, topical antimicrobial lavage and proton-pump-inhibitor (PPI) therapy for transgastric notes.

Methods: Prospective randomized study with 16 pigs. 8 pigs received the following preparation: 40mg Esomeprazole i.v.; mouth lavage with Chlorhexidine 2%, gastric lavage with Chlorhexidine, followed by gastric irrigation with diluted antibiotic containing Neomycin/saline solution as well a single-shot application of Cefuroxim and Metronidazol. Control group (n=8) underwent gastric cleansing with sterile saline solution. Gastrotomy was closed after 2 hours. Prior to closure peritoenal biopsy, multiple smears and dilutions for cultures were taken and incubated. The swine were sacrified after 14 days. Biopsies, smears and cultures as well as WBC and serum CRP were taken in the follow-up. Bacterial load was expressed in Colony-forming units (CFU's).

Results: 15/16 swine survived the follow-up of 14 days. 1 pig (control group) underwent gall bladder perforation with groß peritonitis and had to be sacrified after 3 days. 2/15 swine presented minor clinical signs of infection (all control group). The median serum CRP's were 5,7g/dl (therapy group) and 17,2g/dl (control) (p=0,17). Peritoneal bacterial growth was seen in 1/8 swine of the therapy group and 8/8 swine of the control group (p=0,002). The bacterial load was 20 CFU's/cm² (therapy) vs. 3,2X10⁵ CFU's/cm² (control) (p=0,023). E. coli and Enterococcus were the most common organisms. Major peritonitis was seen in 1, local peritonitis and ahesions were seen in another 2 pigs, all from the control group.

Conclusion: The use of intravenous antibiotics in addition to topical antimicrobial lavage of mouth/stomach and PPI-therapy effectively decreases the peritoneal bacterial load to almost zero and this was associated with a significant lower peritoneal infection rate when compared to saline only lavage.