Simulation in pediatric minimally invasive surgery: adaptation of a simple series of exercises as part of the process of an initial implementation of a resident training program

ABSTRACT Introduction: the simulation in minimally invasive surgery is fundamental for surgeon in training to learning and training skills, especially in pediatrics, due to the particularities, reduced spaces, specific and rare procedures. The aim of this study was to propose an adapted series of exercises and to simply evaluate the performance of pediatric surgery residents in the initial implementation of a training program. Method: seven basic skills exercises in video surgery, based on series and programs already published and using low-cost materials, were performed by six residents in 2 moments, with an interval of 15 days and evaluated by simple instrument. Results: there was no difficulty with models. Considering the individual averages of the seven exercises together in the two moments, five of the six residents increased the score in the second moment. The average score per exercise increased in five of the seven tasks. Despite the small number of participants and repetition, it has already been possible to observe a trend of better performance with decreased time of all residents after a single repetition. All considered the exercises capable of training essential skills of the specialty, with simple and inexpensive materials. Conclusion: given the challenges of simulated training in pediatric video surgery, it is known the benefit of a continuous program, with exercises that can simulate real situations. A pre-established schedule, more participants and repetitions, supervision of experienced surgeons and validated instruments are fundamental to evaluate surgeons in training and show statistical benefits of simulated exercises in this series.


INTRODUCTION
S imulation has been increasingly used as a strategy to allow the learning and training of skills and competencies necessary for professional performance, in a controlled and safe environment for the surgeon and the patient.The possibility of carrying out procedures repeatedly on mannequins and simulators allows errors to be corrected, in addition to enabling technical evolution to be monitored 1 .Aiming to improve skills and minimize risks, simulation training has been highly valued in the health sector, at different levels of training, mainly in the surgical area involving minimally invasive surgeries 2 .
Especially in pediatric surgery, training must include learning complex and rare procedures, neonatal malformations, oncological surgeries, as well as video surgical skills in small cavities, handling delicate tissues and improving finer and more precise movements.
Therefore, safe training is even more necessary due to the particularities of the specialty, which has specific procedures and fewer cases in daily practice.
Several simulation models in pediatric minimally invasive surgery have been described in Silva Simulation in pediatric minimally invasive surgery: adaptation of a simple series of exercises as part of the process of an initial implementation of a resident training program

METHODS
We developed and applied a series of seven exercises to all six residents, two from each year of residency, at the Pediatric Surgery Service of Hospital Pequeno Príncipe, Curitiba, Paraná, Brazil.The series of exercises was based on and inspired by other series and by the North American Fundamentals of Laparoscopic Surgery (FLS) program described in the literature, adapting some exercises to the availability and viability of the models.Another series of exercises, created, selfapplied and self-evaluated by the residents themselves years before, also served as inspiration and basis for the current series 6 .
The six residents received instructions and performed the same series of exercises in two moments ("series 1" and "series 2"), with an interval of approximately 15 days, using a video surgery simulator with a camera (black box), a basic set of laparoscopic instruments (including Maryland, scissors, needle holder, and grasping forceps), one monitor -21.5" screen, portable capture plate (Recorder), surgical sutures (nylon 4.0 and polygalactin 3.0), and acrylic and polystyrene bases, with the models developed by the researchers themselves.
The seven exercises performed are described and illustrated with original photos in Figure 1.The models used are easy to reproduce with simple materials and can be adapted and reproduced in any service.Even exercises 3 and 4 that used a model with a specific shape can be replaced by any structure that allows simple or continuous suturing between two edges, such as models latex balloons.The skills assessed were grasping and transferring objects, transferring a circular object (ring) in a rigid circuit, simple interrupted suture, simple continuous suture, cutting tissue in a pre-defined area, placing objects in a glove finger bag, and translocation of a piece of tissue between two points.
An evaluation instrument containing the objectives of the exercises and assigning grades to each one of them was developed by the authors and filled by the researchers to evaluate the residents' performance in these two moments of activity, as illustrated in Figure 2.
The instrument used was prepared by the authors and adapted for the chosen exercises, as a way of serving as a reference and collecting some objective data regarding the residents' performance.

Data were collected and tabulated in Microsoft
Excel ® spreadsheets and analyzed using the Statistical Package for the Social Science -SPSS ® computer software (IBM ® SPSS ® Statistics v. 25.0, SPSS Inc, Chicago, USA).
The results were expressed as means (quantitative variables).For inferential analyzes, we used the Wilcoxon Non-Parametric Test, considering values of p<0.05 as significant.
This study was conducted after approval by the institution's Ethics and Research Committee, under registration CAAE 03943218.9.0000.5580,and followed the ethical recommendations for research in Ordinance 466/12 of the National Health Council.All participants signed an informed consent form.

All six pediatric surgery residents at Hospital
Pequeno Príncipe at Curitiba participated in the study.There were two residents from each year of specialization, and all performed the series of exercises at the two proposed times and with an interval of approximately 15 days between them, varying from 14 to 17 days, according to guidance.There were no difficulties or problems related to the proposed models and exercises, all of which were easy for participants to understand and evaluate during the study.
Table 1 shows the complete results spreadsheet with the time and scores of the six residents in the seven exercises performed.
Considering the scores, when comparing the participants' individual averages in the seven exercises in both series, five of the six residents increased their scores from the first to the second time they performed the exercises, as illustrated in graph A (Figure 3).
As for the average scores of all residents per exercise in the two moments, when comparing the second moment with the first, a higher result was obtained in five exercises, lower in one exercise (exercise 4) and stayed the same in one (exercise 6).(Graph B -Figure 3) All these values were not statistically significant, with p-values>0.05.Only exercise 2 showed a tendency towards significance between the two repetition moments of the series (p=0.083).Some articles indicate a minimum number of repetitions of an exercise or activity to achieve certain skills, such as at least 30 repetitions for each task 7 or around five sessions in a virtual reality simulator to reach a relatively stable level of knowledge 11,12 .

Figure 1 .
Figure 1.Description and illustration of the exercises.

Figure 3 .
Figure 3. Average grades in both series.Graph A. Average per resident in all exercises.Graph B. Average in each exercise for all residents.

Silva
Simulation in pediatric minimally invasive surgery: adaptation of a simple series of exercises as part of the process of an initial implementation of a resident training program and the one that took longer was number 3 (average of 8 minutes and 50 seconds in the first series and 4 minutes and 27 seconds in second).Exercise 3 was also the only one with statistical significance when we carried out a comparative analysis of time between the first and second series (p=0.027), with a proven reduction in time.Among the basic specific skills required to perform video surgery procedures, there are visual adaptation, notion of depth in a two-dimensional image, and motor skills to manipulate instruments and structures appropriately.Skill acquisition is divided into three stages: 1) Initial (cognitive), with inconsistent movements that require a high degree of attention; 2) Intermediate (associative), with few serious errors, requiring a lower level of attention; 3) Advanced (autonomous), in which there is greater agility, allowing the execution of simultaneous tasks, reaching a level of proficiency 4 .Several training programs with similar structures and different exercises have been created and others are constantly being developed to train and improve the skills needed for minimally invasive surgery.The Laparoscopic Surgical Skills Program (LSS) is an European training program that evaluates simulation based on performance indicators in the surgical field, considering tests of cognitive, technical, and judgment skills 8 .The Fundamentals in Laparoscopic Surgery (FLS), approved by the American College of Surgeons 9 , have become mandatory for first-year surgery residents, including theoretical content and supervised hands-on exams, allowing surgeons in training to evaluate and record their own skills 10,19-21 .

Figure 4 .
Figure 4. Average times in both series.Graph A. Average per resident in all exercises.Graph B. Average in each exercise for all residents.

Figure 5 .
Figure 5. Average scores represented in lines (series 1 dark blue and series 2 light blue).Average times represented in columns (blue series 1 and green series 2) per exercise.
and adapted from other already validated series, with the aim of publicizing the possibility of adaptations to enable the training of laparoscopic skills and to encourage the initial implementation of training programs.The possibility of replicating, in an adapted way, simulation exercises for video surgery skills training, allowed residents to practice and selfevaluate their performance, as well as resulting in better performance observed in some exercises after the second repetition.Although we could not statistically confirm this due to the sample size, it attests to the importance of continued training in a safe and protected environment.CONCLUSIONS Faced with the challenges of promoting effective learning of skills in pediatric minimally invasive surgery, we highlight the benefit of a continuous training program in laparoscopic surgery for residents, with a series of exercises that can be easily reproduced and repeated in simulating real situations, such as those developed in this study.A series of simple exercises with low-cost materials can be easily created for basic skills training.A pre-established schedule with specific objectives, supervision by trained surgeons, and officially validated assessment instruments are essential to analyze the learning curve in each skill taught and ensure training effectiveness.