Critical design and validation considerations for the development of neonatal minimally invasive surgery simulators

Concurrent validity of objective assessment by finger tracking for open surgical suturing training

BACKGROUND

The aim of this study is to evaluate whether the parameters 'time' and 'distance', measured by SurgTrac, correlate with the assessment of the same skills by blinded experts.

METHODS

Basic open suturing tasks were executed by medical students. SurgTrac software measured objective parameters by tracking fingers. The executed tasks were recorded by a tablet and additionally assessed by a blinded expert with a Competency Assessment Tool-form (CAT-form). A Pearson's correlation was used to investigate the correlation between the parameters and the outcomes of the expert assessment.

RESULTS

A strong correlation between the measured parameters of SurgTrac and the expert-assessment was found for knot tying by hand (r ​= ​-0.703) and vertical mattress suture (r ​= ​-0.644) and a moderate correlation for transcutaneous suture (r ​= ​-0.555) and intracutaneous suture (r ​= ​-0.451).

CONCLUSION

The use of finger tracking by SurgTrac showed a good concurrent validity for the basic open suturing tasks knot tying by hand, transcutaneous suture and vertical mattress suture.

Inanimate 3D printed model for thoracoscopic repair of esophageal atresia with tracheoesophageal fistula

Background

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.

Methods

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.

Results

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).

Conclusions

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.

Longitudinal Force Measurement and its Relationship to Technical Competence for Esophageal Anastomosis in a Thoracoscopic Esophageal Atresia/tracheo-esophageal Fistula Simulator

PURPOSE

Thoracoscopic esophageal atresia with tracheo-esophageal fistula (EA/TEF) repair requires the gentle manipulation of delicate tissue. Force sensors were attached to the upper and lower esophagus of a 3D-printed EA/TEF simulator to explore force parameters as markers of performance.

METHODS

Participants completed one intracorporeal suture between the anterior walls of upper and lower esophageal ends. Longitudinal force data were recorded at each end. A blinded pediatric surgeon marked attempt videos. Excessive force events, maximum tension, and force interquartile range (IQR) were measured. Data were reported as median (range) significance of p < 0.05.

RESULTS

17 participants of varying levels of experience performed the task. OSATS scores showed significant differences between experts and novices. Experts completed the task in a median time of 4 min. They used lower maximum tension, higher force IQR, and had fewer excess force events compared to the intermediate and novice groups.

DISCUSSION

The application of force was dependent on expertise with more skilled participants having fewer excess force events. The higher expert force IQR likely reflects the consistent tension needed for task completion. Analysis of force data may be an indicator of competence, and trainees may benefit from a thoracoscopic simulator which provides force data feedback.

LEVEL OF EVIDENCE

Not applicable.

Perioperative outcomes in minimally-invasive versus open surgery in infants undergoing repair of congenital anomalies

BACKGROUND

This study compared perioperative outcomes among infants undergoing repair of congenital anomalies using minimally invasive (MIS) versus open surgical approaches.

METHODS

The ACS NSQIP Pediatric (2013-2018) was queried for patients undergoing repair of any of the following 9 congenital anomalies: congenital lung lesion (LL), mediastinal mass (MM), congenital malrotation (CM), anorectal malformation (ARM), Hirschsprung disease (HD), congenital diaphragmatic hernia (CDH), tracheoesophageal fistula (TEF), hepatobiliary anomalies (HB), and intestinal atresia (IA). Inverse probability of treatment weights (IPTW) derived from propensity scores were utilized to estimate risk-adjusted association between surgical approach and 30-day outcomes.

RESULTS

12,871 patients undergoing congenital anomaly repair were included (10,343 open; 2528 MIS). After IPTW, MIS was associated with longer operative time (difference; 95% CI) (16 min; 9-23) and anesthesia time (13 min; 6-21), but less postoperative ventilation days (-1.0 days; -1.4- -0.6) and shorter postoperative length of stay (-1.4 days; -2.4- -0.3). MIS repairs had decreased risk of any surgical complication (risk difference: -6.6%; -9.2- -4.0), including hematologic complications (-7.3%; -8.9- -5.8). There was no significant difference in risk of complication when hematologic complications were excluded (RD -2.3% [-4.7%, 0.1%]). There were no significant differences in the risk of unplanned reoperation (0.4%; -1.5-2.2) or unplanned readmission (0.2%; -1.2-1.5).

CONCLUSIONS

MIS repair of congenital anomalies is associated with improved perioperative outcomes when compared to open. Additional studies are needed to compare long-term functional and disease-specific outcomes.

MINI-ABSTRACT

In this propensity-weighted multi-institutional analysis of nine congenital anomalies, minimally invasive surgical repair was associated with improved 30-day outcomes when compared to open surgical repair.

LEVEL OF EVIDENCE

III.

The role of motion tracking in assessing technical skill acquisition using a neonatal 3D-printed thoracoscopic esophageal atresia/tracheo-esophageal fistula simulator

INTRODUCTION

Acquiring the technical skills required for thoracoscopic repair of esophageal atresia with tracheo-esophageal fistula (EA/TEF) is challenging. A high-fidelity 3D-printed pediatric thoracoscopic EA/TEF simulator has been developed to address this issue. This study explored motion-tracking as an assessment tool to distinguish between surgeons of different expertise using the simulator.

METHODS

Participants performed a single intracorporeal suture between the esophageal ends in EA with TEF. Total relative path lengths of the right and left surgical instruments were recorded during the task. Each video-recorded attempt was assessed by a blinded pediatric surgeon using a modified Objective Structured Assessment of Technical Skills (OSATS) score. Data recorded as median (range) and statistical significance as p<0.05.

RESULTS

The task was performed by 17 participants. The median OSATS scores identified a significant difference between experts and novices. A difference between left- and right-hands was only found in the mid-skill level group. Right-hand path length was greatest in novices and lowest in experts. Left-hand path length was greatest in novices and the mid-skill level group compared to experts.

CONCLUSION

Experts had the lowest total path length for either hand, suggesting they had the greatest efficiency of movement. The similar high path lengths in both hands for novices indicate their relatively low level of skill with either hand. The difference between right- and left-hand path lengths in the mid-skill level group likely reflects the improved right-handed technical skills in contrast to the still developing left hand. Further focus on the left hand during simulation training may improve left-handed economy of movement.

Step-by-step development and evaluation of a 3D printed home-made low-cost pediatric tracheobronchial tree for foreign body aspiration extractions

OBJECTIVES

The management of foreign body aspirations (FBA) is dreaded by pediatric physicians due to the high risk of respiratory distress and a potential fatal outcome, favored by a lack of experience of young specialists. Furthermore, there has been an increasing requirement for low-cost simulation. The aim was to describe the step-by-step manufacturing process and to validate a low-cost, easily home-made training model of pediatric tracheo-bronchial tree (pTBT) for simulation-based training in order to teach young physicians to practice foreign body (FBA) extractions.

METHODS

A simulator was designed in order to reproduce the physical and esthetic properties of a pTBT. The production cost of a single simulator was estimated. The simulator was then tested by experienced physicians using a rigid bronchoscope. A manufacturing manual of the simulator is hereby presented. A group of 7 experienced pediatric otolaryngologists performed a FBA extraction in the conditions of installation of an operating room.

RESULTS

The result of the survey showed a high fidelity of the simulator in mimicking the biological esthetics and physical properties of a pTBT during a FBA extraction (mean 4.3 ± 0.8). The total cost of the custom-made simulator is about 20.5 € ($23.4) for the production of the first simulator.

CONCLUSIONS

A highly realistic and easily reproducible pediatric tracheo-bronchial tree simulator is presented and can therefore be used during simulation-based training.

Development and validation of a novel 3D-printed simulation model for open oesophageal atresia and tracheo-oesophageal fistula repair

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Designing a synthetic simulator to teach open surgical skills for limb exploration in trauma: a qualitative study exploring the experiences and perspectives of educators and surgical trainees

Background

Simulation is an important adjunct to aid in the acquisition of surgical skills of surgical trainees. The simulators used to adequately enable trainees to learn, practice and be assessed in surgical skills need to be of the highest standards. This study investigates the perceived requirements of simulation and simulators used to acquire skills in limb exploratory procedures in trauma.

Methods

Semi-structured interviews were conducted with an international group of 11 surgical educators and 11 surgical trainees who had experience with surgical simulation. The interviews focused on the perceptions of simulation, the integration of simulators within a curriculum and the features of a simulator itself. Interviews were recorded, transcribed and underwent thematic analysis.

Results

Analysis of the perspectives of surgical educators and surgical trainees on simulated training in limb trauma surgery yielded three main themes: (1) Attitudes to simulation. (2) Implementing simulation. (3) Features of an open skills simulator. The majority felt simulation was relevant, intuitive and a good way for procedure warmup and the supplementation of surgical logbooks. They felt simulation could be improved with increased accessibility and variety of simulator options tailored to the learner. Suggested simulator features included greater fidelity, haptic feedback and more complex inbuilt scenarios. On a practical level, there was a desire for cost effectiveness, easy set up and storage. The responses of the educators and the trainees were similar and reflected similar concerns and suggestions for improvement.

Conclusion

There is a clear positive appetite for the incorporation of simulation into limb trauma training. The findings of this will inform the optimal requirements for high quality implementation of simulation into a surgical trauma curriculum and a reference to optimal features desired in simulator or task trainer design.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-021-01417-7.

Association of operative approach with outcomes in neonates with esophageal atresia and tracheoesophageal fistula

PURPOSE

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

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

LEVEL OF EVIDENCE

III.

Cadaver Training for Minimally Invasive Pediatric Surgery: A Preliminary Report

Aim: To report the value of adult cadavers for training in minimally invasive surgical (MIS) techniques for pediatric surgery (PS). Materials and Methods: Three teams, each consisting of a board-certified consultant pediatric surgeon (CS), a senior trainee (ST), and a junior trainee (JT), attended a cadaver surgical training (CST) course involving five procedures: thoracoscopic esophagoesophagostomy (TEE), thoracoscopic right lower lobectomy (TRL), laparoscopic fundoplication (LFN), laparoscopic hepaticoduodenostomy (LHD), and laparoscopic ureteroureterostomy (LUU). The same teams also performed LFN on live pigs. Attendees (3 CSs, 3 STs, and 3 JTs) were administered a questionnaire to rate their CST experience according to five criteria (tissue texture, organ size, operative field, "feel," and anatomic relationships) using a 4-point scale with 0 being the worst response. Scores were averaged per procedure per attendee groups and compared. LFN was also compared between a cadaver and a pig. Results: End-point (1): For LFN, cadaver scores were significantly higher than pig scores for anatomic relationships (P = .0001), operative field (P = .0053), and organ size (P = .0481). End-point (2): TRL and LFN were ranked together as being most realistic, followed by TEE and LUU, then LHD. End-point (3): Anatomic relationships and operative field consistently scored highly for all attendee groups. End-point (4): CSs and STs tended to award higher scores than JTs although differences were not statistically significant. Conclusions: CST is a valuable opportunity for PS trainees to experience highly realistic training in minimally invasive surgery. Pig training was inferior. IRB Number: 2019173.

Construct validation of a 3D printed neonatal thoracoscopic simulator: Can it measure expertise?

BACKGROUND

acquiring technical expertise for neonatal thoracoscopy is challenging. To address this, we designed a fully synthetic thoracoscopic simulator for which we established its construct validity.

METHODS

three thoracoscopic tasks were assessed: ring transfer, needle pass and incision of a blind upper esophageal pouch (EA cut). Participants watched instructional videos with accompanying written instructions for each task before having their attempt video recorded. All tasks were marked by three blinded pediatric surgeons using a modified Objective Structured Assessment of Technical Skills (OSATS). Scores were assessed using appropriate statistical analysis and inter-rater reliability was analyzed by interclass correlation coefficient (ICC).

RESULTS

23 participants completed the ring transfer and needle pass and 21 the EA cut: 5 experts (consultant surgeons), 5 intermediate (registrars on a training program) and 13 novices (medical students, house surgeons or non-training registrars). All three tasks distinguished between novice and intermediate/expert (ring transfer p = 0.00001, needle pass p = 0.0004 and EA cut p = 0.0014, respectively). Interrater reliability was good for ring transfer and needle pass but poor for EA cut.

CONCLUSION

the tasks distinguished between novice and intermediate/expert but not between expert and intermediate. In needle pass and EA cut, there was a trend for the experts to score higher than intermediate participants. Ring transfer and needle pass tasks achieved construct validity, had good interrater reliability and were found to be useful in assessing a novice surgeon's progression towards the intermediate level. Distinguishing between intermediate and expert may require assessment of more complex tasks such as intracorporeal suturing and tying.

LEVEL OF EVIDENCE

II.

Is Technical Expertise Necessary to Assess Technical Expertise? Let's Ask the Kids

Background: Simulation has an increasing role in surgical training; however, using validated tools such as the Objective Structured Assessment of Technical Skills (OSATS) is time-consuming, which may be a potential barrier to simulation-based training. This study tests the hypothesis that assessors with technical expertise are necessary to objectively score a technical task. Methods: Three tasks, ring transfer, needle pass, and atresia cut, were performed using a synthetic thoracoscopic simulator for esophageal atresia/tracheoesophageal fistula. Three pediatric surgeons, 6 novice adults, and 3 children aged 9-13 years scored each attempt using the overall global OSATS rating from 1 to 5 (1 "repeated or awkward movements" to 5 "fluid movement. No awkwardness"). Results: For the ring transfer, all assessors scored novice participants significantly less than expert and intermediate scores (surgeon P = .0004, nonsurgeon adults P = .0009 and children P = .0003). For the needle pass, all assessors gave significantly different scores between novices and experts (surgeon P = .0007, nonsurgeon adult P = .0008, and children P = .0040). For the atresia cut, surgeon assessors gave significantly higher scores for experts and intermediate and novice (P = .0004). Nonsurgeon assessors gave experts and intermediates significantly higher scores than novices (P = .0001). Surgeon assessors achieved good reliability for ring transfer (0.8252) and needle pass (0.7769) compared with nonsurgeon assessors who showed poor reliability for the ring transfer (0.3959) and moderate for the needle pass (0.6551). Conclusions: Expertise in performing these procedures is not a prerequisite for an assessor to evaluate the technical skill, hence assessors of skill acquisition can be nonexpert, a nonsurgeon, or even a child. The variability in all groups suggests that reliability overall is increased with multiple assessors. Although nonsurgeon assessors may be appropriate for formative assessments, they lack the reliability to provide assessment of competence for high stakes complex tasks. Summative assessment will likely require at least 1 surgeon/expert assessor to provide reliability.

Advanced three-dimensionally engineered simulation model for aortic valve and proximal aorta procedures

OBJECTIVES

A 3-dimensionally (3D) engineered model for simulation of aortic valve and proximal aortic procedures is a reliable tool both for training young surgeons and for simulating complex cases. To achieve a realistic simulation, the artificial model should reproduce the angles and orientations of the cardiac structures based on the patient's anatomical condition, reproduce tissue mechanical characteristics and be easy to obtain and easy to use. The goal of the study was the production and validation of realistic training models, based on the patient's actual anatomical characteristics, to provide training for aortic valve procedures.

METHODS

An anatomical model was manufactured using 3D printing and silicone casting. The digital anatomical model was obtained by segmenting computed tomography imaging. The segmented geometrical images were processed and a casting mould was designed. The mould was manufactured on a 3D printer. Silicone was cast into the mould; after curing, the finished model was ready. The realistic reproduction was evaluated by mechanical hardness tests and a survey by cardiac surgeons.

RESULTS

Six 3D silicone models were produced that represented the patient's anatomy including aortic valve leaflets, aortic root with coronary ostia, ascending aorta and proximal arch. Aortic valve replacement was performed, and 100% of the participants evaluated the model in a survey as perfectly reproducing anatomy and surgical handling.

CONCLUSIONS

We produced a realistic, cost-effective simulator for training purposes and for simulation of complex surgical cases. The model reproduced the real angulation and orientation of the aortic structures inside the mediastinum, permitting a real-life simulation of the desired procedure. This model offers opportunities to simulate various surgical procedures.