[Accessibility of peritoneal organs according to the routes of approach in NOTES]

Natural orifice transluminal endoscopic surgery (NOTES) is a new era of minimally invasive surgery which has the potential to offer scarless surgery. So far, numerous reports on various routes to peritoneal organs in NOTES have been published. In case of transgastric approach, it is more inconvenient than transcolonic approach to access upper abdominal organs because of retroflexion. However, most data were subjective and there was no report examining the best access route for the exploration of peritoneal organs. The aim of this study was to evaluate the best access route according to the abdominal organs objectively.

Six female pigs weighing 30 to 35 kg were placed under general anesthesia. Incisions were made on both anterior wall of stomach body and rectosigmoid colon 15 to 20 cm above anal verge, respectively. Then, via each incision site, we evaluated the endoscopic visibility and checked the elapsed time to access abdominal organs in sequence [(gallbladder (GB), spleen, bladder, uterus, and ovary)].

On comparison of the mean time to approach each organs, GB and ovary showed statistical difference in the mean time to approach between transgastric and transcolonic approaches. It took relatively shorter time to access GB via transcolonic route than transgastric route (352.3+/-80.1 sec vs. 222.2+/-82.0 sec, p=0.021). Next, we evaluated the time to access upper organs (GB and spleen) and lower organs (bladder, uterus and ovary). In case of lower organs, it showed no difference in time between transgastric and transcolonic approaches. However, to explore upper organs, transcolonic route was more favorable than transgastric route (351.8+/-80.7 sec vs. 273.3+/-110.3 sec, p=0.002).

For exploration of lower organs, there is statistically no significant difference in time between transgastric and transcolonic approaches. But, in case of upper organs, transcolonic approach is superior to transgastric approach.