Background: Endoscopic submucosal dissection (ESD) is proving effective in the resection of selected early stage gastrointestinal cancers. Its application and appropriateness could be extended if a means of determining lymphatic dissemination could be provided without recourse to conventional operation. Here we demonstrate the performance of companion sentinel node biopsy (SNB) by Natural Orifice Translumenal Endoscopic Surgery (N.O.T.E.S.) immediately preceding ESD of a site in the sigmoid colon.
Methods: A porcine model was used. An arbitrarily-selected mucosal focus in the sigmoid colon was targeted for combined N.O.T.E.S. SNB as well as the ESD. N.O.T.E.S. peritoneal access was obtained transgastrically using a conventional flexible gastroscope. The sigmoid was retracted by magnetic assistance (an intracolonic magnet was anchored and guided by a second placed extracorporeally). A second intraluminal endoscope was passed per ano and initially performed the submucosal injection of methylene blue dye for the lymphatic mapping under direct vision of the N.O.T.E.S. optic. The N.O.T.E.S. endoscope then identified the first-order draining (‘sentinel’) nodes and allowed their excisional biopsy. After retrieval of the nodes, the sigmoidoscope performed an ESD of a 1cm specimen from the site of lymphatic mapping in a standard fashion. The N.O.T.E.S. optic remained in situ to monitor the performance of this procedure and to guard against inadvertent perforation. After its conclusion, the gastrotomy was closed using the Occluder system. An immediate laparotomy was then performed to assess the adequacy and efficiency of the sentinel node biopsy and to ensure the quality of the ESD.
Results: Three sentinel nodes were identified, biopsied and retrieved intact. ESD was readily performed subsequently without perforation or hemorrhage. SNB completeness and ESD quality was confirmed at post-procedural laparotomy.
Conclusions: While contentious and not yet appropriate for human use, this proposal merits serious consideration as a potential means of augmenting the application, effectiveness and propriety for ESD techniques for colonic neoplasia.
Session: Video Channel
Program Number: V060