A Randomized Trial Comparing Rates of Abdominal Contamination and Postoperative Infection Among Natural Orifice Transluminal Endoscopic Surgery, Laparoscopic Surgery, and Open Surgery in Pigs

Background: Bacterial contamination of the abdominal cavity and infectious complications have been debated concerning transgastric natural orifice transluminal endoscopic surgery (NOTES) procedures.

Objective: The aim of this study was to compare bacterial contamination of the abdominal cavity and clinically relevant infections after open, laparoscopic, and transgastric NOTES procedures.

Design: Randomized survival study in a porcine model.

Setting: Animal laboratory at a university hospital.

Intervention: Thirty pigs were randomized to open, laparoscopic, or transgastric NOTES uterine horn resection under sterile conditions. Bacterial cultures were obtained from the pelvic area immediately at entry of the abdominal cavity and just before closure. The left uterine horn was dissected and ligated. The animals survived for 4 weeks. At necropsy, bacterial culture was obtained from the pelvic area.

Main Outcome Measurements: Perioperative: operation time and incision length, bacterial growth in abdominal samples. Postoperative: infections or complications, weight gain. Necropsy: signs of peritonitis or infection, abdominal bacterial growth.

Results: Procedure time was significantly longer for transgastric NOTES. At the start of the procedure, 4 of the NOTES animals showed positive cultures, but only 1 showed positive cultures at the end. No open surgery or laparoscopic surgery animals showed positive cultures at these time points. At necropsy, none of the animals in the NOTES group showed bacterial growth, whereas 4 open surgery animals and 3 laparoscopic surgery animals had positive cultures. Four of these animals (2 from each group) had concurrent wound infections.

Limitations: Small sample size and lack of power calculation.

Conclusion: This study indicates that clinically relevant infections are rare after transgastric NOTES procedures despite evidence of bacterial contamination and longer operating times.