Per-Oral and Gastrostomy Assisted Full Thickness Gastric Resection Using SurgASSIST® Via a Modified Oro-Esophageal Overtube in a Porcine Model

Abstract

Per-Oral and Gastrostomy Assisted Full Thickness Gastric Resection Using SurgASSIST Via a Modified Oro-Esophageal Overtube in a Porcine Model John a. Evans, Francis E. Rosato, Gregory G. Ginsberg Introduction: Intraluminal full-thickness gastric resection (FTGR) could be applicable for management of early gastric cancer and gastrointestinal stromal tumors. SurgASSIST (Power Medical Interventions, Langhorne, PA) is a computer mediated, electromechanically powered, cutting/stapling device delivered on a flexible and steerable shaft to which interchangeable loading units of varying configuration, length, and application are affixed. Steering of the flex-shaft and operation of loading units are remote controlled. Aim: This feasibility study assessed applicability to intraluminal FTGR in a swine model. Methods: Four nonsurvival swine under general anesthesia were used. An oro-esophageal overtube (ID 27.2 mm/OD 32.2 mm) was placed followed by dual T-tag placement to abut the gastric wall to the abdominal wall. A balloon trochar(10 mm, US Surgical Autosuture) was inserted into the stomach under endoscopic guidance and served as an alternate port for instruments and endoscope (Olympus GIF-160 and XP-160). Under direct visualization the SurgASSISTwith a 55 mm straight-linear-cutter-stapler (SLCS55) loading unit was advanced via the overtube, into the esophagus and then to the stomach. We evaluated safety and efficacy of overtube placement, SLCS55 insertion, maneuverability in the stomach, parallel vs perpendicular optics, and various tissue grasping devices to achieve tenting of the gastric wall within the arms of the SLCS55 and performance of FTGR. Results: Overtube insertion was successful in all subjects and produced no mucosal tears in one, limited in two, and severe in one. The SLCS55 easily traversed the overtube, but required considerable manipulation under retrograde endoscopic visualization to traverse the esophagus and EG-junction. Maneuverability of the SLCS55 in the stomach was limited. Endoscopic guidance for attempted FTGR via both per-oral (parallel) and per gastrotomy port (perpendicular) orientations was satisfactory. Laparoscopic grasping forceps compared favorably to endoscopic grasping forceps. However, the depth of resected tissue could not be reliably predicted until post-resection specimen inspection. A FTGR was successful in two of four subjects. The resected tissues measured 6.0 cm by 1.8 cm and 6.0 cm by 2.1 cm. There was no pneumoperitoneum, intraor extraluminal bleeding, or gastrotomy leak/failure. In the other two, depth of resection was submucosa. One subject arrested intraoperatively. Conclusion: Per-oral intraluminal FTGR is feasible. A large diameter overtube permits per-oral access. A gastrostomy port facilitates device positioning and tissue manipulation. Further refinements are needed to yield reliable results.