“Chopstick” surgery: a novel technique improves surgeon performance and eliminates arm collision in robotic single-incision laparoscopic surgery

Abstract

Introduction

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 × 12 mm, 2 × 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.

Conclusion

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.

Appendix 1. FLS manual skills score sheet

• 1. PEG transfer (timing starts once first object is grasped, ends after last PEG is transferred)

  Time to complete: seconds

  PEGS not transferred:

• 2. Pattern cut (timing starts when gauze is grasped and ends when circle is cut completely)

  Time to complete: seconds

  Area of penalty: squares covered

• 3. Intracorporeal knot (timing starts when you see instruments inside the box, ends when both sutures are cut)

  Time to complete: seconds

  Penalty: mm from edge of predrawn dots

  Security of knot.