Transgastric pure-NOTES peritoneoscopy and endoscopic ultrasonography for staging of gastrointestinal cancers: a survival and feasibility study.

BACKGROUND: Human natural orifice transluminal endoscopic surgery (NOTES) has mainly been based on simultaneous laparoscopic assistance (hybrid NOTES), forgoing the theoretical benefits of the NOTES technique. This is due to a lack of NOTES-specific instruments and endoscopes, making pure-NOTES procedures difficult and time consuming. An area where pure NOTES could be adopted at its present stage of development is minimally invasive staging of gastrointestinal (GI) cancer. The aim of this study is to evaluate the feasibility of combining transgastric (TG) pure-NOTES peritoneoscopy and intraperitoneal endoscopic ultrasonography (ip-EUS) with intraluminal EUS (il-EUS) for peritoneal evaluation.
METHODS: This was a feasibility and survival study where il-EUS followed by ip-EUS and peritoneoscopy was performed in 10 pigs subjected to TG pure NOTES. A score was given with regard to achieved visualisation of predefined anatomical structures. Survival was assessed at postoperative day (POD) 14.
RESULTS: All animals survived until POD 14. Median total procedural time was 94 min (range 74-130 min). Median time for il-EUS, ip-EUS and peritoneoscopy was 11 min (range 7-14 min), 13 min (range 8-20 min) and 10 min (range 6-23 min). Il-EUS, ip-EUS and peritoneoscopy resulted in a score of 15/15 points (range 14-15 points), 6/9 points (range 1-8 points) and 12/13 points (range 8-13 points).
CONCLUSIONS: TG pure-NOTES peritoneoscopy and ip-EUS combined with il-EUS is feasible and provides sufficient peritoneal evaluation. The technique could have potential for minimally invasive staging of GI cancers.