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Effects of Repetition and Inactivity on Laparoscopic Skills Training

Published:September 18, 2015DOI:https://doi.org/10.1016/j.jmig.2015.09.008

      Abstract

      Study Objective

      To describe the impact of task repetition and time between practice sessions on time to complete a surgical task using a high-fidelity laparoscopic simulator.

      Design

      An Institutional Review Board–approved retrospective cohort study of 33 obstetrics/gynecology residents with unlimited access to a high-fidelity laparoscopic simulator over a period of 12 months. Canadian Task Force design classification II-2.

      Setting

      Academic medical center and obstetrics/gynecology residency training program.

      Participants

      Obstetrics/gynecology residents.

      Interventions

      Participation in a high-fidelity laparoscopic training exercise.

      Measurements

      Residents completed a standardized peg transfer exercise with data collected on the time to completion of the exercise, number of the attempt, and interval since the last day of practice. Data were analyzed using Spearman correlation coefficients and mixed-effects linear regression.

      Main Results

      A total of 33 residents participated during the 12-month period, completing 484 peg transfer exercises (mean, 16.2 per resident). Each repetition was correlated with a mean decrease in time to completion of 2.28 seconds (p < .0001). This correlation was most dramatic in the first 9 completed exercises, in which each repetition correlated with a decrease in time to complete of 7.98 seconds (p ≤ .0001). The lapse in practice preceding the exercise correlated with a negligible change in time to completion of 0.003 second (SD, 0.06; p = .90).

      Conclusion

      The number of previous completed exercises was significantly correlated with decreased time to completion of this standardized exercise. Lapses in practice did not correlate with slower times to completion, suggesting that repetitive exposure to a simple surgical task has a greater impact on efficiency than lapse in practice.

      Keywords

       Discuss

      You can discuss this article with its authors and with other AAGL members at http://www.AAGL.org/jmig-23-1-JMIG-D-15-00310.
      Achieving proficiency and excellence in surgery requires repetition, creativity, and decision making skills typically provided to trainees during postgraduate training. With the widespread adoption of minimally invasive techniques and a trend toward nonsurgical interventions for many conditions, resident physicians are tasked with learning and exploring a wide range of technologies with fewer opportunities to refine their skills before graduation.
      Simulation-based surgical training aims to shift the early learning curve of a new technology or procedure out of the operating room to a venue where rapid repetition is possible. Several studies have supported the idea that teaching through high-fidelity laparoscopic simulation correlates with operative performance [
      • Bonrath E.M.
      • Weber B.K.
      • Fritz M.
      • et al.
      Laparoscopic simulation training: testing for skill acquisition and retention.
      ,
      • McDougall E.M.
      • Corica F.A.
      • Boker J.R.
      • et al.
      Construct validity testing of a laparoscopic surgical simulator.
      ,
      • Palter V.N.
      • Grantcharov T.P.
      Individualized deliberate practice on a virtual reality simulator improves technical performance of surgical novices in the operating room: a randomized controlled trial.
      ]. One randomized double-blinded study demonstrated that surgical interns who completed a series of exercises on the Lap Mentor trainer performed with greater speed and accuracy on a porcine model compared with interns without simulator experience [
      • Andreatta P.B.
      • Woodrum D.T.
      • Birkmeyer J.D.
      Laparoscopic skills are improved with LapMentor training: results of a randomized, double-blinded study.
      ]. A prospective blinded randomized controlled trial conducted in Denmark compared the technical performance of first- and second-year trainees in performing laparoscopic salpingectomy with or without simulator training. Trainees exposed to the simulator completed 28 sessions and approximately 7 hours of practice on average. These trainees demonstrated proficiency equivalent to having completed 20 to 50 laparoscopic procedures, whereas those without training performed as if they had completed fewer than 5 laparoscopic procedures. In addition, their operative times were halved [
      • Larsen C.R.
      • Soerensen J.L.
      • Grantcharov T.P.
      • et al.
      Effect of virtual reality training on laparoscopic surgery: randomized controlled trial.
      ].
      Fewer studies have sought to learn more about how simulated learning occurs. In a study by Sheth et al [
      • Sheth S.S.
      • Fader A.N.
      • Tergas A.I.
      • Kushnir C.L.
      • Green I.C.
      Virtual reality robotic surgical simulation: an analysis of gynecology trainees.
      ], gynecology trainees of all levels demonstrated improved efficiency in repeating simple tasks 10 times each on a robotic skills simulator. The authors noted that trainees reached a plateau in time to complete the exercise between the sixth and ninth repetitions. Actual resident education occurs over time, however, and few studies have explored whether trainees experience a degradation of skills during periods of inactivity. Burchard et al [
      • Burchard E.R.
      • Lockrow E.G.
      • Zahn C.M.
      • Dunlow S.G.
      • Satin A.J.
      Simulation training improves resident performance in operative hysteroscopic resection techniques.
      ] found that hysteroscopy operative times were longer at 6 months after residents completed a simulation exercise. This certainly suggests that residents experience attenuation of skills over time, but does not tell us how quickly these skills degrade and what time intervals are ideal for maintaining surgical skills. As simulation becomes an increasingly important part of the residency curriculum, we need to better understand how skills are maintained, to optimize resident surgical training.
      The primary aim of the present study was to describe the rate of improvement in surgical skills with repetitive completion of a basic exercise on a high-fidelity surgical trainer using the standard outcome of time to completion of a task. Our secondary aim was to describe how skills degrade during periods of inactivity so that we may better integrate learning patterns into a more optimal training curriculum.

      Materials and Methods

      This was an Institutional Review Board–approved retrospective cohort study of obstetrics/gynecology residents at a single institution participating in laparoscopic training using the Lap Mentor simulator (Simbionix, Cleveland, OH) over a 12-month period. The simulator was made available to residents for practice at all hours of the day, and access was unlimited. During the study period, residents did not have any access to any additional high-fidelity laparoscopic simulators. This high-fidelity laparoscopic trainer features various skill modules, including several components of the Fundamentals of Laparoscopic Surgery. We selected the peg transfer exercise as our standardized exercise for analysis because it is a straightforward task for residents of all levels to complete, and the most commonly completed task at our institution. Completion of the exercise requires the user to transfer 6 rings on pegs to a second set of 6 pegs, then back to the first set of pegs. The exercise was completed when all pegs were successfully transferred back to the initial set of pegs (Fig. 1).
      Figure thumbnail gr1
      Fig. 1The peg transfer exercise on the LapMentor high-fidelity laparoscopic simulator.
      Data were collected directly from the simulator and included participant identification number, residency year, practice session number, exercise number, day of exercise, and the time to exercise completion. The lapse in practice was calculated as the time in days between the last day on which the exercise was completed by that participant and the current day of practice. Analysis was completed with SAS version 9.3 (SAS Institute, Cary, NC). Spearman correlation coefficients were used to describe the association between time to completion and the variables of repetition number and lapse in practice, because these data were not normally distributed. Mixed-effects linear regression was used to isolate the effects of both repetition and lapse on the primary outcome of time to completion, because we anticipated a likely effect of both repetition and time lapse on the time to complete a given exercise.

      Results

      A total of 33 obstetrics/gynecology residents completed the peg transfer exercise over the 12-month period, including 21 junior-level residents (postgraduate years 1 and 2) and 12 senior-level residents (postgraduate years 3 and 4). A total of 484 peg transfer exercises were completed during this time period (mean per resident, 16.2 ± 18.3, range, 1–72) (Table 1). The mean time for completing the exercise was 101 seconds. Senior residents completed the exercise in less time (mean, 85 seconds vs 106 seconds for junior residents), although the difference was not statistically significant (p = .3174). Exercises were repeated over various periods of inactivity. The shortest time interval between practice sessions was 1 day, and the longest period of inactivity was 231 days. The mean number of days between the first day of practice and any given practice day was 80.4 days.
      Table 1Completion of the peg transfer exercise by training year
      CharacteristicAll residentsJunior residentsSenior residents
      Number332112
      Exercises completed, mean (SD)16.2 (18.3)18.5 (17.5)12.2 (19.4)
      Exercises completed, range1-721-591-72
      Time to complete, s, mean (SD)100.7 (57.8)105.9 (58.9)85.2 (51.2)
      For all completed exercises, each repetition of the exercise was associated with a decreased time to completion of 2.34 seconds (SD, 0.31; p < .001). Lapse was associated with a decrease in time to completion by 0.003 second (SD, 0.06; p = .90). Time to completion improved more significantly with initial repetitions of the exercise (Table 2). For the first 9 repetitions, each repetition was associated with a decreased time to completion of 7.98 seconds (p < .0001), and lapse was associated with a negligible decrease of 0.13 second (p = .40). For repetitions 10 to 39, each repetition was associated with a decreased time to completion of 1.10 seconds (p < .0001), and lapse was associated with an increase in time to completion of 0.0014 second (p = .90).
      Table 2Change in time to completion of the exercise by repetition and lapse in days
      PredictorRepetitions 1–9Repetitions 10–39
      Change in time to complete, sp valueChange in time to complete, sp value
      Repetition−8.62<.0001−1.10<.0001
      Lapse, days−0.41.0036−0.07.05
      Both
       Repetition−7.98<.0001−1.10<.0001
       Lapse−0.13.400.0014.90

      Discussion

      When we set out to document resident performance in completing this basic simulation task, we anticipated that our data would demonstrate improved efficiency with repetitive exposure to an exercise, as well as predictable degradation of skills over periods of inactivity. We hoped this would help us to formulate a simulation curriculum dedicated to maintaining resident laparoscopic skills and improving performance in the operating room. As expected, we saw a dramatic improvement in time of completion with increased repetitions of the exercise (Fig. 2). In addition, the SD of time to completion decreased in parallel with the time to completion of the exercise, suggesting that variability in performance also decreases with repetition. This implies that repetition offers both increases in efficiency and consistency for the learner. Importantly, we saw the greatest improvement in skills within the first 10 repetitions of the exercise, indicating that repetition was essential to early mastery of a new skill. Similar trends have been described in robotic simulation data reported by Sheth et al [
      • Sheth S.S.
      • Fader A.N.
      • Tergas A.I.
      • Kushnir C.L.
      • Green I.C.
      Virtual reality robotic surgical simulation: an analysis of gynecology trainees.
      ], in which gynecology trainees completing a robotic simulation exercise reached a plateau in time to complete a basic task after 6 repetitions. In both the present study and the study by Sheth et al, it seems that mastery of a simple operative skill occurs early on with repeated exercise.
      Figure thumbnail gr2
      Fig. 2Time to completion (with corresponding SD) of the peg transfer exercise as a function of the number of repetitions of the exercise.
      We were also interested to see how well skills would be maintained over periods of inactivity. A previous randomized trial found that medical students learning a laparoscopic suturing technique maintained a higher skill level if they had monthly simulation sessions compared with students who had no practice over the 5-month follow-up period [
      • Van Bruwaene S.
      • Schijven M.P.
      • Miserez M.
      Maintenance training for laparoscopic suturing: the quest for the perfect timing and training model. A randomized trial.
      ]. However, resident education in particular is unique in that learners rotate through operative rotations over the course of an academic year, and have exposure to basic surgical skills even in their first year of training. For these reasons, we expected that their experience in learning new surgical tasks might be different from that of a medical student's experience. We expected to see a predictable slowing of completion time when residents experienced gaps in practice; however, our data review revealed a paradoxical decrease in time to completion with increasing periods of inactivity. When we controlled separately for both repetition and lapse, each repetition correlated with a faster time, and a lapse of 1 day correlated with a negligible change. The number of times that the exercise was repeated was the main driver of the improved efficiency, and the effect of lapse in practice was minimal. This suggests that repetitive practice is more critical to performance of a simple surgical task than practice at timed intervals.
      Strengths of the present study include the use of a standardized laparoscopic exercise, the large number of completed exercises, and the use of a high-fidelity laparoscopic simulator that has been researched previously and found to correlate with improved resident operative performance [
      • Andreatta P.B.
      • Woodrum D.T.
      • Birkmeyer J.D.
      Laparoscopic skills are improved with LapMentor training: results of a randomized, double-blinded study.
      ]. Our study is limited to a single institution, and our inclusion of residents at all levels precludes us from interpreting whether skills learning for interns differs from that of senior residents. In addition, the retrospective nature of the study made it impossible to control for resident exposure to operative laparoscopy during the study period, which may have confounded our results. We limited our primary outcome to completion time and elected not to look at variables, such as instrument path length, that may have better conveyed economy of movement. This was specifically a simulation exercise, and the study design made it impossible to assess resident operative performance during the study period. Thus, we can deduce information only on resident skills learning, and not on operating room performance. Although our data provide information on basic skills learning, patterns of skill retention of a simple task might not correlate with the learning and retention of more complex skills required to complete complicated surgical cases [
      • Nagendran M.
      • Gurusamy K.S.
      • Aggarwal R.
      • Loizidou M.
      • Davidson B.R.
      Virtual reality training for surgical trainees in laparoscopic surgery.
      ].

      Conclusion

      Our data indicate that residents acquire surgical skills through repetitive practice, and that lapses in practice are not associated with a predictable loss of simple skills. Much of the current literature in simulation is drawn from the testing of standardized curricula, which focus on interval simulation over specified periods of time. Our results suggest that simulated learning should focus on completing an established number of repetitions of an exercise, rather than on completing scheduled sessions at intervals. More research is certainly needed on the impact of simulation training on resident performance as simulation becomes a greater part of resident surgical education. Although our data suggest that repetitive practice on a simulator leads to improved efficiency in completing an exercise, we need more data on how simulated practice impacts operating room performance and ultimately patient outcomes.

      Acknowledgments

      We thank the Women & Infants Simulation Program for their assistance with this study, and especially our simulation coordinators, Robin Shields and Jai-Me Potter-Rutledge.

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