Endoscopic Submucosal Dissection of Gastric Lesion By Using a Master and Slave Transluminal Endoscopic Robot (MASTER): A Survival Study

DAVIDE LOMANTO, MD PhD FAMS Surg, SOO JAY PHEE, PhD, RAJAT GOEL, MBBS MS DNB, ANDY PRIMA KENCANA, B Eng, SOON CHIANG LOW, PhD, kHEK YU-HO, MD. Dep.of Surgery and Dept. Of Medicine, Y L L School of Medicine, National University of Singapore; School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore

Endoscopic Submucosal Dissection (ESD) was first performed in Japan for enbloc curative resection of early gastric cancers. Currently, ESDs are mostly performed by using a standard endoscope with endoscopically developed knives. There are limited degrees of freedom for endoluminal maneuvers of instruments deployed through accessory channels of the endoscope. Performing ESD thus requires a tremendous amount of skill on the part of endoscopiost and makes it prone to procedural complications. More dexterous endoscopic equipment is needed to make the performance of ESD easier and safer. This study explored the feasibility of using a highly dexterous Master and Slave Transluminal Endoscopic Robot (MASTER) to mitigate the technical challenges of the performance of ESD in a survival study. Five female pigs (32.4-36.8 kg) underwent ESD using the MASTER. All the animals survived for 2 weeks and were then euthanized and necropsy was performed. Main Outcomes measured were completeness of resection, time for resection, procedure related complications, survival at 2 weeks, secondary outcomes measured were peritoneal contamination, intra-abdominal abscess. Operative technique:Gastric lavage was done first through the normal gastroscope introduced through the overtube. The lesion was then marked with IT diathermic knife, and was elevated with submucosal injection of a mixture of 40 ml normal saline with 0.5 ml Methylene blue. The conventional endoscope was then removed and a dual-channel therapeutic endoscope with the MASTER mounted was introduced into the stomach. By using the robotic grasper to hold the elevated lesion, a peripheral mucosal incision was made by using the monopolar electrocautery hook at a circumferential margin of 1cm from the demarcated area. Once completed, the mucosal flap was lifted with the grasper. Dissection was executed in a single lateral direction until completion, and the entire lesion was excised en bloc, the stomach was inspected for any perforation and bleeding. The procedure was successfully completed in a mean time of 21.8 min (range 6-39 min) the mean dimensions of the lesions was 77.14mm (range 25-104.6). 1pig had intra-operative small perforation that was identified and successfully clipped. After 2 weeks survival, the animals underwent gastroscopy and subsequently euthanasia. All lesions were healed at gastroscopy and at necropsy, there was no peritoneal contamination or abscess and the stomach was completely healed which was confirmed microbiologically and pathologically. In conclusion the MASTER exhibited good grasping and cutting efficiency throughout. Surgical maneuvers were achieved with ease and precision. There was no incidence of excessive bleeding or stomach wall perforation.The study demonstrated for the first time that the MASTER could effectively improve the performance of ESD shortening time and complications.