title: Comparison of the Effect of Instrument Type on Transanal Endoscopic Surgery Learning Curves.
abstract: 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.
authors.affiliation: Department of Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL.
authors.forename: Ezra N
authors.initials: EN
authors.lastname: Teitelbaum
authors.forename: Fahd O
authors.initials: FO
authors.lastname: Arafat
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Boller
mesh_terms: D002983:Clinical Competence / Q000592:standards*; D004503:Education, Medical, Graduate / Q000379:methods; D006801:Humans; D010535:Laparoscopy / Q000193:education / Q000295:instrumentation* / Q000592:standards; D059032:Learning Curve; D061646:Operative Time; D011351:Proctoscopy / Q000193:education / Q000295:instrumentation* / Q000592:standards; D000066908:Simulation Training / Q000379:methods; D013337:Students, Medical