Natural Orifice Trangastric Endoscopic Segmental Hepatectomy Using a Through-the-Scope Intuitively Controlled Robotics-Enhanced Manipulator System

Abstracts

than traditional surgery. Despite relative elevations of surgical stress markers, NOTES animals appeared less painful and experienced an uneventful postoperative recovery. Therefore NOTES may represent an alternative to open or laparoscopic surgery in these animals. Further studies are warranted. )This study was conducted in compliance with the Purdue Animal Care and Use Committee, Purdue University, West Lafayette, IN.))The study is supported by a grant from NOSCAR/ASGE

S1395 Natural Orifice Trangastric Endoscopic Segmental Hepatectomy Using a Through-the-Scope Intuitively Controlled RoboticsEnhanced Manipulator System Khek Yu Ho, Louis S. Phee, Davide Lomanto, Soon Chiang Low, Van An Huynh, Andy P. Kencana, Kai Yang, Mahdi Rasouli, Sheung Chee Sydney Chung Background and Aims: The parallelism of standard endoscopic fixtures limits the degree of freedom for surgical maneuvers during Natural Orifice Transluminal Endoscopic Surgery (NOTES). This study explored the feasibility of adapting an intuitively-controlled robotics-enhanced endosurgical system we developed to facilitate hepatectomy in NOTES. Methods: The system comprises a master controller, a telesurgical workstation, and a slave robotic manipulator. The master is attached to the wrists and fingers of the operator through an array of sensors and joints. The slave comprises 2 manipulators - a grasper and a mono-polar cautery hook which are separately inserted through the operating channels (2.8 mm, 3.7 mm diameters) of a gastroscope. Movements of the operator detected by sensors are actuated into force signals to drive the manipulators via a tendon-sheath mechanism. The procedure was performed on a 35 kg female pig under general anesthesia. The gastroscope with robotic manipulators was passed into the stomach via an overtube. Entry into the peritoneal cavity was made through a 10 mm incision on the anterior wall of the stomach. Access to the liver segment was made by retroflexing the endoscope at a 45 degrees angle. Segmental hepatectomy was performed using the grab and cut functions of the robotic grasper and hook, respectively. Hemostasis was achieved with the hook. Gastrotomy was left open and the animal was euthanized. Results: Transgastric segmental hepatectomy was successfully performed using the robotic system with no laparoscopic assistance. The entire operation was completed in 8.5 min, with 2.5 min spent on gastrotomy and endoscopic access to target site, and 6 min spent on excision of the liver segment. The robotic grasper was able to effectively grab and retract the liver while the cautery hook dissected the liver. Coordination of the two end-effectors was precise and triangulation of the two manipulating arms was achieved with ease. The liver segment, which was excised in one piece, measured 21  10  7.6 mm. Parenchymal bleeding was adequately controlled by electrocautery using the hook, and this was achieved in 1.2 min. The resected liver segment was retrieved whole through the open gastrotomy and removed through the mouth using the grasper. Conclusion: This study demonstrated for the first time the through-the-scope robotics-enhanced endosurgical system could effectively mitigate the technical constraints normally encountered in NOTES procedures. With it, the triangulation of surgical tools and manipulation of tissue become easy and the entire operation could be successfully accomplished without the need of laparoscopic assistance.

S1396 A Two Micron Continuous Wave Laser System Is Safe and Effective for Peritoneal Access & High Precision Dissection During NOTESÒ Procedures Xavier Dray, Gianfranco Donatelli, Devi Mukkai Krishnamurty, Ronald J. Wroblewski, Lia R. Assumpcao, Samuel A. Giday, Jonathan M. Buscaglia, Eun Ji Shin, Elena Dubcenco, Priscilla Magno, Laurie J. Pipitone, Michael R. Marohn, Sergey V. Kantsevoy, Anthony N. Kalloo Thulium lasers (TLs) have a 2 mm wavelength that matches the water absorption peak allowing efficient tissue cutting with limited thermal damage but have not been evaluated in the gastrointestinal tract. TLs are very flexible with an outer diameter of 365 to 550 mm enabling use as a guide wire. Objective: To evaluate the safety and efficacy of TLs for transcolonic and transgastric access for NOTES and to determine the ability to dissect tissue during NOTES procedures. Methods: Six acute animal experiments. Group 1 (3 animals): TL was used for transcolonic access to the peritoneal cavity by puncture of the colonic wall with insertion of the TL probe as a guide wire followed by balloon dilation over TL probe. Group 2 (3 animals): TL was used for transgastric access to the peritoneal cavity (similar technique as group 1) followed by laser-assisted dissection of the caudal pole of the kidney. In one animal of group 2 a therapeutic target (hematoma) was created by percutaneous puncture trauma of the kidney. Results: Translumenal access to the peritoneal cavity was achieved in 2 to 3 minutes in group 1 and in 7 to 10 minutes in group 2. In group 2, laser dissection of the parietal peritoneum & perinephric connective tissue was quick and efficient allowing easy access to the retroperitoneum with complete removal of a blood collection in the animal with

AB162 GASTROINTESTINAL ENDOSCOPY Volume 69, No. 5 : 2009

puncture trauma. TL dissection demonstrated clean and rapid cutting, and excellent hemostasis. Peritoneoscopy and necropsy showed no damage to adjacent tissue and surrounding organs. Conclusions: The 2 mm continuous wave laser system was safe and effective for peritoneal access with ability to perform precise and safe dissection during NOTES procedures.

S1397 Transgastric Versus Laparoscopic Ventral Hernia Repair: A Randomized Controlled Trial in a Live Porcine Model Sergey V. Kantsevoy, Xavier Dray, Eun Ji Shin, Gianfranco Donatelli, Devi Mukkai Krishnamurty, Jerome Lyn-Sue, Anirban Gupta, Samuel A. Giday, Jonathan M. Buscaglia, Andrew Zhigalin, Ronald J. Wroblewski, Michael R. Marohn, Michael A. Schweitzer Background: Ventral hernia repair is currently performed via open or laparoscopic surgery approaches. Translumenal ventral hernia repair has been recently reported in an animal model. Objective: To compare transgastric and laparoscopic ventral hernia repair techniques. Methods: We performed 10 survival experiments on 50-kg pigs. Abdominal wall hernias were created through a 5 mm skin incision followed by 5cm long incision of the abdominal wall muscles and aponeurosis. All animals were survived for 2 weeks and then they were randomly assigned to either transgastric or laparoscopic hernia repair. In the laparoscopic repair group (5 animals), a Gore-TexÒ mesh was delivered into the peritoneal cavity through a 12mm laparoscopic trocar and attached to the abdominal wall with transfascial anchor sutures to repair the previously created abdominal wall hernia. In the transgastric repair group (5 animals), transgastric peritoneoscopy was performed and then a Gore-TexÒ mesh was delivered into the peritoneal cavity through the gastric wall incision and attached to the abdominal wall with transfascial anchor sutures to repair the previously created abdominal wall hernia. Then the flexible endoscope was withdrawn into the stomach and the gastric wall opening was closed with T-bars. Animals in both groups were survived for another 2 week period and then sacrificed. Results: Ventral hernias were created without technical problems and all animals developed large abdominal ventral hernias after 2 weeks of observation. Ventral hernias were successfully repaired via transgastric or laparoscopic approaches in all animals. Adhesiolysis prior to hernia repair was required in 2 animals in the laparoscopic and in 3 animals in the transgastric repair group. Time needed for hernia repair was comparable (pZ 0.08) in both groups: 60.8  9.8 minutes (laparoscopic) versus 75.8  7.0 minutes (transgastric repair). During necropsy intraperitoneal adhesions were found in 3 animals (60%) of each group. Necropsy also demonstrated 2 seromas under the mesh in the laparoscopic repair group and only 1 seroma in the transgastric repair group. In addition, there was an infected hematoma at the site of 12-mm trocar insertion in 1 animal in the laparoscopic repair group. There were no other complications in the transgastric repair group. Conclusion: Transgastric and laparoscopic ventral hernia repair appear equally fast and effective. However, the transgastric approach is less invasive than laparoscopic and may eliminate complications related to the insertion of the 12-mm laparoscopic trocar.

S1398 The Development and Testing of An Adaptable MinimallyInvasive Surgical Platform - The Hydra Per-Ola Park, Maria Bergstro ¨m, Asghar Azadani, Omar J. Vakharia, Robert Trusty, John Elliott, Gregory J. Bakos, Kurt R. Bally, Paul Swain Introduction: Progress has been made in developing new platforms for NOTES, but limitations in stability, instrumentation, navigation, closure, and triangulation, as identified by NOSCAR, remain to be addressed. Interest in less-invasive surgery beyond laparoscopy has also expanded beyond NOTES into approaches such as Single Site Laparoscopy (SSL), enabled by both rigid and flexible instruments. New platforms, capable of adaptation to a range of developing surgical approaches, seem necessary. Methods: Clinicians and engineers partnered together to develop a new platform, the Hydra, which is adaptable to transgastric and transvaginal hybrid/pure NOTES approaches, as well as SSL. The foundation of the platform is a multidirectional Steerable Flexible Trocar (15 mm internal diameter) that allows navigation to the targeted area. The Trocar is passed into the peritoneal cavity via a needle knife/ balloon; through it, an operative tool with three 4mm channels is advanced. Two of these channels articulate independently in multiple directions, allowing triangulation. The third channel carries a unique 3.7 mm, joystick-controlled, endoscope (Karl Storz EndoVision, Charlton, MA) that can be elevated over the articulating channels, providing a view independent of the operative tools. The system is controlled by a laparoscopy-like interface that allows a surgeon to use 2 hands to manipulate at least 2 tools with degrees of freedom not available in conventional endoscopes. Changes in system length and flexibility can be made to accommodate a variety of surgical approaches. Additional tools under development include a range of flexible staplers, next-generation closure, and remote retraction. The entire Toolbox of NOTES devices, including Bela bipolar forceps, a clip applier, flexible Marylands, etc., is compatible with the Hydra. Results: The Hydra has been used in a series of 8 acute porcine labs via transgastric and transvaginal approaches. Pure NOTES uterine horn resection and hybrid cholecystectomy are feasible. The

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