Reply to Linghu et al.

We thank Dr. Linghu for his interest in our paper [1].

Briefly, we performed aseptic procedures in the same manner as those in a routine surgical operation. We completely disinfected the operative field and the endoscopic route from the oral cavity to the gastric cavity. First, we placed a split barrel (TOP Corp., Tokyo, Japan) to enable the insertion of two endoscopes. Then, using the disinfectant povidine iodine, we disinfected the patient’s entire face and the mouth piece connected to the overtube. Through the overtube, a conventional endoscope was used to place a duodenal balloon into the stomach. After proper balloon placement, the endoscope was removed while spraying 1 % povidine iodine over the balloon, gastric cavity (antrum, corpus, and fundus), esophagus, and overtube. At this point, the endoscope was considered to be contaminated, and thus a second endoscope that had been sterilized with ethylene oxide gas was inserted while spraying sodium thiosulfate hydrate to neutralize the povidine iodine. After completely neutralizing the povidine iodine, we used physiological saline to wash the gastric cavity, esophagus, and overtube. We then completed the sterilization routine by aspirating accumulated fluid in the gastric cavity.

Although we are currently investigating whether adequate disinfection is provided by 1 % povidine iodine alone, we have never had a case of postoperative infection. In addition, before and during surgery, endoscopists wash their hands and follow the same aseptic steps practiced by surgeons. Patients positive for Helicobacter pylori undergo an eradication procedure prior to surgery. Although the gastric cavity is almost sterile because of its low pH after H. pylori eradication, we still perform the above antiseptic procedures as a precautionary measure. Furthermore, during the operation we aspirate fluid as frequently as possible to prevent potential fluid leakage into the abdominal cavity. After surgery, we operate a laparoscope to close the incision site and wash the abdominal cavity with 3 – 4 L of physiological saline [2].

As we emphasized, we are very careful about infection, and owing to the above-mentioned steps, none of our cases to date have experienced postoperative infection [3] [4]. We use three endoscopes – one for disinfection and the other two for operating under aseptic conditions. Although interference between endoscopes is minimal because of the split barrel, we are currently in the process of developing a longer overtube, which we believe will further reduce interference.

References

• 1 Mori H, Kobara H, Kobayashi M et al. Establishment of pure NOTES procedure using a conventional flexible endoscope: review of six cases of gastric gastrointestinal stromal tumors.  Endoscopy. 2011;  43 631-634
• 2 Giday S A, Dray X, Magno P et al. Infection during natural orifice transluminal endoscopic surgery: a randomized, controlled study in a live porcine model.  Gastrointest Endosc. 2010;  71 812-816
• 3 Hazey J W, Needleman B J, Melvin W S et al. Transgastric instrumentation and bacterial contamination of the peritoneal cavity.  Surg Endosc. 2008;  22 605-611
• 4 Narula V K, Happel L C, Volt K et al. Transgastric endoscopic peritoneoscopy does not require decontamination of the stomach in humans.  Surg Endosc. 2009;  23 1331-1336