Comparison of the Effect of Instrument Type on Transanal Endoscopic Surgery Learning Curves

Background: Transanal endoscopic surgery (TES) can be technically difficult due to the constraints of operating through a narrow proctoscope channel. In this study, we compared the performance of surgical novices using instruments with and without articulating shafts to perform a simulated TES task. Methods: Medical students each performed 10 repetitions of the Fundamentals of Laparoscopic Surgery circle-cut task. Participants were randomized into 3 groups: 2 performed the task through a TES proctoscope using scissors with either a rigid (TES-R) or articulating (TES-A) shaft. The third group performed the task laparoscopically (LAP). Results: A total of 31 medical students participated. The LAP group had a faster mean task time than both the TES-R and TES-A groups (LAP 201±120 s vs. TES-R 362±212 s and TES-A 405±212 s, both P <0.001). The TES-R group made more errors (ie, deviation from a perfect circle) than both the other groups. The TES-R group adjusted the proctoscope position during more repetitions than the TES-A group. Conclusions: Students had faster task times when operating laparoscopically than through a TES protoscope. Task times were similar between the TES groups using scissors with articulating and rigid shafts; however, use of the articulating instruments resulted in fewer errors and less need to adjust proctoscope position.