Simulation is an educational tool that can be used to augment surgical training. We sought to provide an overview of existing pediatric surgical simulation models, with a focus on low-cost models amenable for use in low-resource settings.

PubMed and Google Patents were searched for studies describing simulation models for pediatric surgery. Studies were included if cost, construct validity, face validity, or reproducibility were described, and if the model was either already utilized in low-resource settings or amenable for use in low-resource settings.

A total of 18 studies and 7 patents were included. Over half (58.3 %) of the models were created in the last five years. Only four models were created in an upper-middle income country, and none were created in a low or lower-income middle income country (LMIC) (16.7 %). Most models were designed for general pediatric surgical procedures, with esophageal atresia repair being the most common procedure (20.8 %). The cost of models ranged between $0.61 USD to $301.44 USD, and cost per simulation episode ranged from $0.61 to $38 USD. Seven models (41.1 %) were 3D printed. Thirteen models (54.2 %) were simulators for minimally-invasive procedures. Sixteen models (66.7 %) were deemed to be reproducible based on their descriptions in published manuscripts or available patents.

The utilization of simulation models in pediatric surgery is growing. Unfortunately, there are few validated models that can be used for training in low-resource settings. Significant work remains to be done on developing educational simulation tools for pediatric surgery in low-resource settings.

This study aimed to develop an esophageal atresia (EA) model using fresh sheep esophagus, trachea, and lungs to simulate a realistic thoracoscopic surgical environment.

A thoracoscopic trainer box was used with fresh sheep tissues (esophagus, trachea, and lungs) to create an EA and tracheoesophageal fistula (TEF) model. The distal esophagus was anastomosed to the trachea, and a bicycle pump was integrated to simulate lung function. Additional components, such as a simulated azygos vein and parietal pleura, enhanced the model's realism for surgical training.

The developed EA-TEF model was created in six steps, including pleural dissection, azygos vein control, TEF division, and esophageal anastomosis. The procedure used a thoracoscopic trainer box, sheep tissues, and standard instruments. A bicycle pump simulated lung function, and careful techniques were employed for vein ligation and esophageal anastomosis. After the posterior wall was sutured, an 8 Fr feeding tube was inserted. The total cost of the model was $260, with reusable equipment and a $10 recurring cost for sheep tissues.

This study successfully developed a cost-effective and anatomically accurate thoracoscopic model for EA and TEF repair using fresh sheep tissue.

Magnetic compression anastomosis is a promising treatment option for patients with complex esophageal atresia; but, at the present time, should not be the first therapeutic option in those cases where the surgeon can perform a primary anastomosis of the two ends of the esophagus with acceptable tension.

We developed a 3D-printed thoracoscopic surgery simulator for esophageal atresia with tracheoesophageal fistula (EA-TEF) and assessed its effectiveness in educating young pediatric surgeons. Prototype production and modifications were repeated five times before producing the 3-D printed final product based on a patient's preoperative chest computed tomography. A 24-item survey was used to rate the simulator, adapted from a previous report, with 16 young surgeons with an average of 6.2 years of experience in pediatric surgery for validation. Reusable parts of the thoracic cage were printed to combine with replaceable parts. Each structure was fabricated using diverse printing materials, and subsequently affixed to a frame. In evaluating the simulator, the scores for each factor were 4.33, 4.33, 4.27, 4.31, 4.63, and 4.75 out of 5, respectively, with the highest ratings in value and relevance. The global rating was 3.38 out of 4, with ten stating that it could be used with slight improvements. The most common comment from participants was that the esophageal anastomosis was close to the actual EA-TEF surgery. The 3D-printed thoracoscopic EA-TEF surgery simulator was developed and reflected the actual surgical environment. It could become an effective method of training young pediatric surgeons.

Thoracoscopic repair of esophageal atresia (EA) and tracheoesophageal fistula (TEF) poses significant technical challenges. This study aimed to develop an inexpensive, reusable, high-fidelity synthetic tissue model for simulating EA/TEF repairs and to assess the validity of the simulator.

By using 3D printing and silicone casting, we designed an inexpensive and reusable inanimate model for training in thoracoscopic EA/TEF repair. The objective was to validate the model using a 5-point Likert scale and the Objective Structured Assessment of Technical Skills (OSATS) to evaluate participants' surgical proficiency.

A total of 18 participants (7 medical students, 4 pediatric surgery trainees, and 7 experienced surgeons), after being instructed and trained, were asked to perform TEF ligation, dissection, as well as esophageal anastomosis using six sliding knots on the EA/TEF simulator. All participants in the expert group completed the task within the 120-minute time limit, however only 4 (57%) participants from the novice/intermediate completed the task within the time limit. There was a statistically significant difference in OSATS scores for the "flow of task" (p = 0.018) and scores for the "overall MIS skills" (p = 0.010) task distinguishing between novice and intermediates and experts. The simulator demonstrated strong suitability as a training tool, indicated by a mean score of 4.66. The mean scores for the model's realism and the working environment were 4.25 and 4.5, respectively. Overall, the face validity was scored significantly lower in the expert group compared to the novice/intermediate groups (p = 0.0002).

Our study established good face and content validity of the simulator. Due to its reusability, and suitability for individual participants, our model holds promise as a training tool for thoracoscopic procedures among surgeons. However, novices and trainees struggled with advanced minimally invasive surgical procedures. Therefore, a structured and focused training curriculum in pediatric MIS is needed for optimal utilization of the available training hours.

The present study clarified the efficacy of repeating laparoscopic surgery training using a disease-specific simulator and investigated the clinical outcomes of laparoscopic surgery for congenital biliary dilatation (CBD) in pediatric patients after training.

A high-fidelity laparoscopic hepaticojejunostomy simulator was used. Four pediatric surgeons performed practice laparoscopic hepaticojejunostomy three times using the simulator. The details of forceps manipulation during the task were analyzed. The clinical outcomes of 13 CBD cases treated with laparoscopic surgery in our institution were also evaluated based on medical records.

The time required to complete the task became significantly shorter each successive time (1st: 1062.18 ± 346.79 s vs. 3rd: 717.44 ± 260.80 s, p = 0.039). There were no significant differences in the total path length of the right forceps (1st: 55.56 ± 23.21 m vs. 3rd: 28.25 ± 17.01 m, p = 0.17), total path length of the left forceps (1st: 47.79 ± 20.79 m vs. 3rd: 31.83 ± 17.62 m, p = 0.17), average velocity of the right forceps (1st: 58.78 ± 21.29 mm/s vs.44.98 ± 10.25 mm/s, p = 0.47), or the average velocity of the left forceps (1st: 50.39 ± 19.25 mm/s vs. 52.26 ± 19.59 mm/s, p = 0.78). Regarding the clinical outcome, all CBD patients underwent laparoscopic surgery performed by practiced pediatric surgeons who had no experience. The operative time was 545.53 ± 91.01 min, and the blood loss was 24.2 ± 25.8 ml. There were no cases of open conversion, intraoperative adverse events, or anastomotic leakage.

Disease-specific simulator training significantly decreased the task performance time by improving the forceps manipulation economy. In addition, simulator training may improve the operative safety and quality of laparoscopic hepaticojejunostomy in pediatric CBD patients.

This review evaluates the validation and availability of simulation models in the field of pediatric surgery that can be used for training purposes.

MEDLINE and EMBASE were searched for studies describing a simulation models in pediatric surgery. Articles were included if face, content and/or construct validity was described. Additionally, the costs and availability were assessed. Validation scores for each model were depicted as percentage (0-100), based on the reported data, to compare the outcomes. A score of >70% was considered adequate.

Forty-three studies were identified, describing the validation process of 38 simulation models. Face validity was evaluated in 33 articles, content in 36 and construct in 19. Twenty-two models received adequate validation scores (>70%). The majority (27/38, 70%) was strictly inanimate. Five models were available for purchase and eleven models were replicable based on the article.

The number of validated inanimate simulation models for pediatric surgery procedures is growing, however, few are replicable or available for widespread training purposes.

Level II.

With reductions in training time and intraoperative exposure, there is a need for objective assessments to measure trainee progression. This systematic review focuses on the evaluation of trainee technical skill performance using objective assessments in cardiothoracic surgery and its incorporation into training curricula.

Databases (EBSCOHOST, Scopus and Web of Science) and reference lists of relevant articles for studies that incorporated objective assessment of technical skills of trainees/residents in cardiothoracic surgery were included. Data extraction included task performed; assessment setting and tool used; number/level of assessors; study outcome and whether the assessments were incorporated into training curricula. The methodological rigour of the studies was scored using the Medical Education Research Study Quality Instrument (MERSQI).

Fifty-four studies were included for quantitative synthesis. Six were randomized-controlled trials. Cardiac surgery was the most common speciality utilizing objective assessment methods with coronary anastomosis the most frequently tested task. Likert-based assessment tools were most commonly used (61%). Eighty-five per cent of studies were simulation-based with the rest being intraoperative. Expert surgeons were primarily used for objective assessments (78%) with 46% using blinding. Thirty (56%) studies explored objective changes in technical performance with 97% demonstrating improvement. The other studies were primarily validating assessment tools. Thirty-nine per cent of studies had established these assessment tools into training curricula. The mean ± standard deviation MERSQI score for all studies was 13.6 ± 1.5 demonstrating high validity.

Despite validated technical skill assessment tools being available and demonstrating trainee improvement, their regular adoption into training curricula is lacking. There is a need to incorporate these assessments to increase the efficiency and transparency of training programmes for cardiothoracic surgeons.

In the context of the COVID-19 pandemic and social distancing rules, access to in-person training activities had temporarily been interrupted, speeding up the implementation of telesimulation for minimally invasive surgery (MIS) essential skills training (T-ESTM, Telesimulation - Essential Skills Training Module) in our center. The aim of this study was to explore the effectiveness of T-ESTM.

T-ESTM was scheduled into 2 sessions of 3 h through the Zoom® virtual meeting platform. The academic lectures, the tutorials for box-trainer set-up and 7 performance tasks were accessed through an online campus previous to the remote encounter for personalized guidance and debriefing. Initial (pre-telementoring) and final (post 6-hour telementoring) assessment scoring as well as timing for Task 2 (circle-cutting pattern), 3 (extracorporeal Roeder knot) and 5 (intracorporeal Square knot) were registered.

61 participants were recruited. The mean age was 31±5 years. 65% were surgical residents. 48% performed low complexity procedures. 52% had previous experience with simulation training. In Task 2, there was a 21% improvement in the final score obtained, as well as a significant decrease in time of 33%; in Task 3, there was an increase of 39% in the scoring and a decrease of 49% in the timing; and in Task 5, participants improved their technique a 30% and decreased the performance time a 47%. All the differences were statistically significant.

Our data support T-ESTM as a reproducible and effective educational tool for remote MIS essential skills hands-on training.

II.

Until now, there have been few tools to evaluate whether a surgeon was technically ready to perform a safe pancreaticojejunostomy (PJ). In the current study, we aimed to evaluate whether a three-dimensional model could mimic a real surgical situation and distinguish between surgeons of different levels of experiences.

A three-dimensional PJ dry laboratory model was printed. Eight experienced pancreatic surgeons were tasked to evaluate the appearance and tactile sensation of the model. Proficiency was scored based on 15 surgeons with various levels of pancreatic experience performing a PJ on the three-dimensional model. Additionally, the time of manipulation and NASA Task Load Index (NASA-TLX) scores were recorded for each operation.

Our study was conducted in multimedical centre in China.

Compared with real surgical situations, this model had similar appearance (3.96±0.55 out of five points) and tactile sensation (3.85±0.46 out of five points) according to the expert evaluation. Additionally, the chief surgeon group scored the best in proficiency (based on NASA-TLX scores and operative time), and there were statistical differences for performances among surgeons of various levels (p<0.05).

The three-dimensional PJ model could mimic a real surgical situation and can distinguish between surgeons of different levels of experiences.

The role of simulation training in paediatric surgery is expanding as more simulation devices are designed and validated. We aimed to conduct a training needs assessment of UK paediatric surgical trainees to prioritise procedures for simulation, and to validate a novel 3D-printed simulation model for oesophageal atresia and tracheo-oesophageal fistula (OA-TOF) repair.

A questionnaire was sent to UK trainee paediatric surgeons surveying the availability and utility of simulation. The operation ranked as most useful to simulate was OA-TOF repair. 3D-printing techniques were used to build an OA-TOF model. Content, face and construct validity was assessed by 40 paediatric surgeons of varying experience.

Thirty-four paediatric surgeons completed the survey; 79% had access to surgical simulation at least monthly, and 47% had access to paediatric-specific resources. Perceived utility of simulation was 4.1/5. Validation of open OA-TOF repair was conducted by 40 surgeons. Participants rated the model as useful 4.9/5. Anatomical realism was scored 4.2/5 and surgical realism 3.9/5. The model was able to discriminate between experienced and inexperienced surgeons.

UK paediatric surgeons voted OA-TOF repair as the most useful procedure to simulate. In response we have developed and validated an affordable 3D-printed simulation model for open OA-TOF repair.

Shifting the training from the operating room (OR) to simulation models has been proven effective in enhancing patient safety and reducing the learning time to achieve competency and increase the operative efficiency. Currently the field of pediatric surgery only offers few low-cost trainers for specialized training and these feature predominantly artificial and often unrealistic tissue. The aim of this study was to develop an easy access low-cost tissue-realistic simulation model for open training of esophageal atresia and to evaluate the acceptance in trainees and junior pediatric surgeons.

The model is fashioned using reconfigured chicken skin from a chicken leg. To create a model of esophageal atresia, the chicken skin is dissected off the muscle and reconfigured around a foley catheter balloon to recreate the proximal pouch and a feeding tube to recreate the distal pouch. Surrounding structures such as the tracheo-esophageal fistula and the azygos vein can be easily added, obtaining a realistic esophageal atresia (Type C) prototype. Evaluation of model construction, usage and impact on user were performed by both a self-assessment questionnaire with pre- and post-training questions as well as observer-based variables and a revised Objective Structured Assessment of Technical Skills (OSATS) score.

A total of 10 participants were constructing and using the model at two different timepoints. OSATS score for overall performance was significantly higher (p = 0.005, z = -2.78) during the second observational period [median (MD): 4,95% confidence interval CI: 3.4, 5.1] compared to the first (MD: 3, 95% CI 2.4, 4.1). Self-reported boost in confidence after model usage for performing future esophageal atresia (EA) repair and bowel anastomosis (BA) in general was significantly higher (EA: U = 1, z = -2.3, p = 0.021, BA: U = 1, z = -2.41, p = 0.016) in participants with more years in training/attending status (EA MD:5, BA MD: 5.5) compared to less experienced participants (EA MD: 1.5, BA: 1).

Our easy access low-cost simulation model represents a feasible and tissue realistic training option to increase surgical performance of pediatric surgical trainees outside the OR.

We sought to evaluate the impact of thoracoscopic repair on perioperative outcomes in infants with esophageal atresia and tracheoesophageal fistula (EA/TEF).

The American College of Surgeons National Surgical Quality Improvement Program pediatric database from 2014 to 2018 was queried for all neonates who underwent operative repair of EA/TEF. Operative approach based on intention to treat was correlated with perioperative outcomes, including 30-day postoperative adverse events, in logistic regression models.

Among 855 neonates, initial thoracoscopic repair was performed in 133 (15.6%) cases. Seventy (53%) of these cases were converted to open. Those who underwent thoracoscopic repair were more likely to be full-term (p = 0.03) when compared to those in the open repair group. There were no significant differences in perioperative outcome measures based on surgical approach except for operative time (thoracoscopic: 217 min vs. open: 180 min, p<0.001). A major cardiac comorbidity (OR 1.6, 95% CI 1.2-2.1; p = 0.003) and preoperative ventilator requirement (OR 1.4, 95% CI 1.0-1.9; p = 0.034) were the only risk factors associated with adverse events.

Thoracoscopic neonatal repair of EA/TEF continues to be used sparingly, is associated with high conversion rates, and has similar perioperative outcomes when compared to open repair.

III.

Minimal invasive surgery (MIS) is increasingly used for the correction of congenital diaphragmatic hernia (CDH) and esophageal atresia (EA). It is important to master these complex procedures, preferably preclinically, to avoid complications. The aim of this study was to validate recently developed models to train these MIS procedures preclinically.

Two low cost, reproducible models (one for CDH and one for EA) were validated during several pediatric surgical conferences and training sessions (January 2017-December 2018), used in either the LaparoscopyBoxx or EoSim simulator. Participants used one or both models and completed a questionnaire regarding their opinion on realism (face validity) and didactic value (content validity), rated on a five-point-Likert scale.

Of all 60 participants enrolled, 44 evaluated the EA model. All items were evaluated as significantly better than neutral, with means ranging from 3.7 to 4.1 (p < 0.001). The CDH model was evaluated by 48 participants. All items scored significantly better than neutral (means 3.5-3.9, p < 0.001), with exception of the haptics of the simulated diaphragm (mean 3.3, p = 0.054). Both models were considered a potent training tool (means 3.9).

These readily available and low budget models are considered a valid and potent training tool by both experts and target group participants.

Prospective study.

Level II.

Background: To increase complex minimally invasive skills (MIS), frequent training outside the clinical setting is of uttermost importance. This study compares two low-cost pediatric MIS simulators, which can easily be used preclinically. Materials and Methods: The LaparoscopyBoxx is a portable simulator without a tracking system, with costs ranging from €90 to €315. The EoSim simulator has a built-in camera and tracking system and costs range from €780 to €1800. During several pediatric surgical conferences and workshops (January 2017-December 2018), participants were asked to use both simulators. Afterward, they completed a questionnaire regarding their opinion on realism and didactic value, scored on a five-point Likert scale. Results: A total of 50 participants (24 experts and 25 target group, one unknown) evaluated one or both simulators. Both simulators scored well on the questionnaire. The LaparoscopyBoxx scored significantly better regarding the "on screen representation of the instrument actions" (mean 4.2 versus 3.5, P = .001), "training tool for pediatric surgery" (mean 4.4 versus 3.9, P = .005), and "appealing take-home simulator" (mean 4.6 versus 4.0, P = .002). Conclusion: The simulators tested in this study were both regarded an appealing take-home simulator. The LaparoscopyBoxx scored significantly better than the EoSim, even though this is a low budget simulator without tracking capabilities.

Pediatric surgical trainees have limited exposure to advanced minimally invasive surgery (MIS) during their clinical training, particularly for cases such as esophageal atresia/tracheoesophageal fistula (EA/TEF). Simulation on validated neonatal models offers an alternative means of training that may augment traditional forms of training; but to be useful, they must fulfill certain criteria.

Review of the currently available MIS, thoracoscopic and laparoscopic, simulators for pediatric surgery, and identification of those factors that contribute to their fidelity and validity as a training tool that must be incorporated in the design of future simulation models.

There are few neonatal laparoscopic and thoracoscopic models currently available, or in the research stage. To our knowledge, there is no commercially available, synthetic, high fidelity and low cost thoracoscopic model in existence. Use of animal tissue has disadvantages of ethical dilemmas, cost, and logistic and procurement issues. Newer synthetic models need to be validated for fidelity, to replicate those components of the operation that pose the greatest technical challenge, and incorporate means of measuring acquisition of technical expertise.

This review describes the principles that need to be considered to develop low cost, validated high-fidelity MIS simulator that can be used for training, and that is capable of measuring the acquisition of the technical skills that can be applied to the repair of complex procedures such as esophageal atresia. Level of evidence III.

Thoracoscopic repair (TR) of esophageal atresia (EA) has been performed with increasing frequency over the last two decades, with the expectation of improved outcomes by avoiding thoracotomy. To understand the current practice and outcomes of TR of EA, we reviewed the relevant literature, including 15 case series, 7 comparative studies, and 3 meta-analysis comparing TR with conventional open repair (COR). Most of the studies had a retrospective design and small numbers of patients. Although the evidence level is low because of the lack of prospective studies, this review found that TR is as safe as COR, with comparative outcomes. Moreover, there were several advantages of TR over COR, such as less blood loss and a shorter hospital stay. The long-term outcomes of TR remain unclear because of limited data. Moreover, there is a significant learning curve over the first 10-20 TRs performed. We conclude that TR of EA, when conducted by experienced surgeons, is a safe and minimally invasive alternative to COR and may yield better results than COR in appropriately selected patients.

The aim of this study was to identify (1) the type of skill evaluation methods and (2) how the effect of training was evaluated in simulation-based training (SBT) in pediatric surgery.

Databases of PubMed, Cochrane Library, and Web of Science were searched for articles published from January 2000 to January 2017. Search concepts of Medical Subject Heading terms were "surgery," "pediatrics," "simulation," and "training, evaluation."

Of 5858 publications identified, 43 were included. Twenty papers described simulators as assessment tools used to evaluate technical skills. Reviewers differentiated between experts and trainees using a scoring system (45%) and/or a checklist (25%). Simulators as training tools were described in 23 papers. While the training's effectiveness was measured using performance assessment scales (52%) and/or surveys (43%), no study investigated the improvement of the clinical outcomes after SBT.

Scoring, time, and motion analysis methods were used for the evaluation of basic techniques of laparoscopic skills. Only a few SBT in pediatric surgery have definite goals with clinical effect. Future research needs to demonstrate the educational effect of simulators as assessment or training tools on SBT in pediatric surgery.

Simulation based training enables pediatric surgical trainees to attain proficiency in surgical skills. This study aims to identify the currently available simulators for pediatric surgery, assess their validation and strength of evidence supporting each model.

Both Medline and EMBASE were searched for English language articles either describing or validating simulation models for pediatric surgery. A level of evidence (LoE) followed by a level of recommendation (LoR) was assigned to each validation study and simulator, based on a modified Oxford Centre for Evidence-Based Medicine classification for educational studies.

Forty-nine articles were identified describing 44 training models and courses. Of these articles, 44 were validation studies. Face validity was evaluated by 20 studies, 28 for content, 24 demonstrated construct validity and 1 showed predictive validity. Of the validated models, 3 were given an LoR of 2, 21 an LoR of 3 and 12 an LoR of 4. None reached the highest LoR.

There are a growing number of simulators specific to pediatric surgery. However, these simulators have limited LoE and LoR in current studies. The lack of NoTSS training is also apparent. We advocate more randomized trials to validate these models, and attempts to determine predictive validity.

Original / systematic review.

1.

We aimed to develop and validate a low cost, do-it-yourself model for neonatal thoracoscopic congenital diaphragmatic hernia (CDH).

Volunteers with varying skills in neonatal minimally invasive surgery tested and evaluated the model simulating a neonatal thoracoscopic CDH repair. The model was built from ordinary materials purchased in a dime store: a small food container, a neoprene band simulating a diaphragm, an inflated balloon simulating a spleen, a tissue chord simulating intestine, and a body wash sponge simulating a collapsed lung. The evaluation comprised 3 sets of 5-point grading scale concerning appearance, necessary maneuvers, and ability to generate skills. Bowel reduction and suture efficacy was verified for each test.

Minimally invasive surgery simulation room at Pediatric Surgery Department of Hospital Universitario de Vall d'Hebron, Barcelona, Spain.

Volunteer residents and specialists of pediatric surgery.

Bowel reduction was possible in every test, with 1 spleen rupture, 1 bowel entrapment, and 2 inappropriate sutures due to tension. Most volunteers considered the general endoscopic vision (63.2%), external and internal dimensions (both 89.5%) to be highly similar; bowel reduction (68.4%) and diaphragm's manipulation and suture (57.9%) to be highly or very highly similar. Regarding its ability to generate skills, most considered it to be very or extremely useful concerning: camera handling (52.6%), working in small spaces and suture (both 100%), and tissue handling (63.2%). The least liked features were the colors and the diaphragm's tension. The size, portability, and the reproducibility were the most liked features.

We consider this low cost and easily reproducible model to be realistic enough for CDH repair training, having the potential to be adapted for other simulations.