title: "Chopstick" surgery: a novel technique improves surgeon performance and eliminates arm collision in robotic single-incision laparoscopic surgery.
abstract: BACKGROUND
  Single-incision laparoscopic surgery (SILS) is limited by the coaxial arrangement of the instruments. A surgical robot with wristed instruments could overcome this limitation, but the arms often collide when working coaxially. This study tests a new technique of "chopstick" surgery to enable use of the robotic arms through a single incision without collision.
  
  
  METHODS
  Experiments were conducted utilizing the da Vinci S robot (Intuitive Surgical, Inc., Sunnyvale, CA) in a Fundamentals of Laparoscopic Surgery (FLS) box trainer with three laparoscopic ports (1 x 12 mm, 2 x 5 mm) introduced through a single "incision." Pilot work determined the optimal setup for SILS to be a triangular port arrangement with 2-cm trocar distance and remote center at the abdominal wall. Using this setup, five experienced robotic surgeons performed three FLS tasks utilizing either a standard robotic arm setup or the chopstick technique. The chopstick arrangement crosses the instruments at the abdominal wall so that the right instrument is on the left side of the target and the left instrument on the right. This results in separation of the robotic arms outside the box. To correct for the change in handedness, the robotic console is instructed to drive the "left" instrument with the right-hand effector and the "right" instrument with the left. Performances were compared while measuring time, errors, number of clutching maneuvers, and degree of instrument collision (Likert scale 1-4).
  
  
  RESULTS
  Compared with the standard setup, the chopstick configuration increased surgeon dexterity and global performance through significantly improved performance times, eliminating instrument collision, and decreasing number of camera manipulations, clutching maneuvers, and errors during all tasks.
  
  
  CONCLUSIONS
  Chopstick surgery significantly enhances the functionality of the surgical robot when working through a small single incision. This technique will enable surgeons to utilize the robot for SILS and possibly for intraluminal or transluminal surgery.
authors.affiliation: Department of Surgery, The Methodist Hospital, Methodist Institute for Technology, Innovation and Education, Weill Cornell Medical College of Cornell University, 6550 Fannin St, SM 1661, Houston, TX 77030, USA. rajoseph@tmhs.org
authors.forename: Rohan A
authors.initials: RA
authors.lastname: Joseph
authors.forename: Alvin C
authors.initials: AC
authors.lastname: Goh
authors.forename: Sebastian P
authors.initials: SP
authors.lastname: Cuevas
authors.forename: Michael A
authors.initials: MA
authors.lastname: Donovan
authors.forename: Matthew G
authors.initials: MG
authors.lastname: Kauffman
authors.forename: Nilson A
authors.initials: NA
authors.lastname: Salas
authors.forename: Brian
authors.initials: B
authors.lastname: Miles
authors.forename: Barbara L
authors.initials: BL
authors.lastname: Bass
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Dunkin
mesh_terms: D019544:Equipment Failure Analysis / Q000379:methods*; D006801:Humans; D010535:Laparoscopy / Q000379:methods*; D010865:Pilot Projects; D012371:Robotics / Q000295:instrumentation*; D025321:Surgery, Computer-Assisted / Q000295:instrumentation*; D013647:Task Performance and Analysis