Bimanual coordination in natural orifice transluminal endoscopic surgery: comparing the conventional dual-channel endoscope, the R-Scope, and a novel direct-drive system.

BACKGROUND: The devices used for natural orifice transluminal endoscopic surgery procedures are endoscopes or inspired by endoscopic design, which makes it difficult to accomplish bimanual coordination. OBJECTIVE: We evaluated 3 operating systems in simulated natural orifice transluminal endoscopic surgery procedures requiring complex bimanual coordination. DESIGN: Operators were required to perform an identical bimanual task by using 3 operating systems: a dual-channel endoscope (DCE); the R-Scope, which has 2 elevators for independent movement of endoscopic instruments; and the Direct Drive Endoscopic System (DDES), which allows separation of instruments and vision, emulating more of a laparoscopic surgery paradigm. SETTING: A bench-top simulation was used. Twelve teams were recruited for DCE and R-Scope testing. Twelve individuals participated in the DDES setup. The task included 3 steps: picking up a ring, passing it between endoscopic instruments, and placing it on a designated location. MAIN OUTCOME MEASUREMENTS: Task performance was evaluated by movement speed and accuracy. RESULTS: Task performance was significantly faster when using the DDES system (29 +/- 28 seconds) compared with the other operating systems (DCE: 140 +/- 55 seconds, R-Scope: 160 +/- 71 seconds; P < .001). The difference between the DCE and the R-Scope was not significant (P = .370). CONCLUSION: Designs that separate vision and motion have more degrees of freedom at the tip of the instruments, and an ergonomic user interface provides benefits for bimanual performance compared with more traditional endoscopic designs. With the DDES, a single operator can perform complex endoscopic tasks faster than 2 operators with a DCE or R-Scope.