Endoscopic submucosal dissection: a cognitive task analysis framework toward training design

The Current Landscape of Endoscopic Submucosal Training in the United States

PURPOSE OF REVIEW

Endoscopic submucosal dissection (ESD) has been found to increase en bloc and R0 resection as well as decrease risk of recurrence. However, despite literature supporting the benefits of endoscopic submucosal dissection, adoption of ESD in the United States has been challenging, driven by factors including requirement for specialized training as well as limitations in training availability.

RECENT FINDINGS

Many devices have been developed to improve ease and therefore adoption for the procedure, with advancements in stability, resection as well as closure of the mucosal defect following resection. While the Japanese model of training in ESD centers around the Master-Apprentice model, this is scarce in the United States. Most US endoscopists therefore must follow other paths to learn and become proficient at ESD. There has been a rapid expansion in literature on ESD, fellowship programs, opportunities for case observation, and significant evolution in ex vivo training models that can assist an endoscopist in receiving training in ESD. Currently, there are three main ways of learning to perform ESD in the United States: 1. Third space endoscopy fellowship; 2. Master-apprentice model; 3. Utilization of live courses and proctored procedures. ESD is the optimal method to ensure en bloc resection of large mucosal neoplasms of the gastrointestinal tract. While several barriers hinder adoption of ESD in the United States, there has been significant development both in procedural and training aspects. Further research and discussions are needed to determine criteria for credentialing and proficiency in ESD.

Orthodontic Rubber Band Traction Improves Trainees' Learning Curve of Colorectal Endoscopic Submucosal Dissection: A Prospective Randomized Study

INTRODUCTION

Colorectal endoscopic submucosal dissection (ESD) is a technically demanding operation with a long learning curve. The aim of this study was to determine whether orthodontic rubber band (ORB)-assisted colorectal ESD could improve the trainees' learning curve as it was shown to shorten colorectal ESD procedure time in trainees and experts.

METHODS

This prospective, randomized, controlled clinical study involved 178 patients who underwent colorectal ESD, randomly divided into trainee ORB-assisted ESD (Trainee ORB-ESD; n = 60), trainee conventional ESD (Trainee C-ESD; n = 57), and expert conventional ESD (Expert C-ESD; n = 61) groups. The main outcome was procedure time.

RESULTS

Per Protocol analysis showed a similar operative time in the trainee ORB-ESD and expert C-ESD groups, which was shorter than in the trainee C-ESD group [28.0 (21.0-35.0) and 25.0 (15.0-35.0) vs 41.0 (31.0-52.5) min; ( P < 0.001)]. The trainee ORB-ESD, trainee C-ESD, and expert C-ESD groups differed significantly in resection speed (11.35, 9.07, and 12.56 mm 2 /min, respectively), good visual field exposure rate (96.7%, 80.7%, and 93.4%), and muscle injury rate (5.0%, 17.5%, and 6.6%). However, the trainee ORB-ESD and expert C-ESD groups were similar in these measures, and all 3 groups were similar in adverse events, en bloc resection, R0 resection, and pathology rates. The cumulative sum suggested that the learning inflection point of the trainee ORB-ESD group was earlier than that of the trainee C-ESD group.

DISCUSSION

ORB-ESD shortened colorectal ESD procedure time and improved efficiency in trainees to an expert level. ORB-ESD could shorten the learning curve, justifying its widespread application.

Cognitive Task Analysis of Escharotomy

INTRODUCTION

With the Army's emerging doctrine of prolonged field care, and with burns being a common injury among soldiers, non-expert providers must be trained to perform escharotomy when indicated. However, the existing physical simulators and training protocols are not sufficient for training non-experts for performing effective escharotomy. Hence, to provide guidance in developing realistic escharotomy simulators and effective training protocols suitable for prolonged field care, a cognitive task analysis (CTA) is needed. This work aims to obtain educative information from expert burn surgeons regarding escharotomy procedures via the CTA.

MATERIALS AND METHODS

The CTA was done by interviewing five subject matter experts with experience in performing escharotomy ranging from 20 to over 100 procedures and analyzing their responses. Interview questions were developed to obtain educative information from expert burn surgeons regarding the escharotomy procedure. A "gold standard protocol" was developed based on the CTA of each of the subject matter experts.

RESULTS

The CTA helped identify general themes, including objectives, conditions that mandate escharotomy, signs of successful escharotomy, precautions, challenges, decisions, and performance standards, and specific learning goals such as the use of equipment, vital signs, performing the procedure, and preoperative and postoperative care. A unique aspect of this CTA is that it identifies the background information and preparations that could be useful to the practitioners at various levels of expertise.

CONCLUSIONS

The CTA enabled us to compile a "gold standard protocol" for escharotomy that may serve as a guide for practitioners at various levels of expertise. This information will provide a framework for escharotomy training systems and simulators.

Endoscopic submucosal dissection training: evaluation of an ex vivo training model with continuous perfusion (ETM-CP) for hands-on teaching and training in China

BACKGROUND

The existing ex vivo models of endoscopic submucosal dissection (ESD) cannot simulate intraoperative hemorrhage well. We aimed to establish an ESD training method by applying an ex vivo training model with continuous perfusion (ETM-CP).

METHODS

Four training sessions were conducted for 25 novices under the guidance of 2 experts. Eventually, 10 novices completed ESD operations on a total of 89 patients after the training. The resection effectiveness, resection speed, complication rate, and novice performance before and after the training were compared. The data regarding the effects of the training and the model were gathered through a questionnaire survey.

RESULTS

In terms of the simulation effect of the model, ETM-CP was evaluated as similar to the live pig in all aspects (P > 0.05). The questionnaire analysis revealed that the ESD theoretical knowledge, skill operation, and self-confidence of novices were improved after the training (P < 0.05). The resection time per unit area had a correlation with the number of training periods (rs = - 0.232). For novice performance, the resection time per unit area was shortened (P < 0.05). There was no difference in patient performance between the novice group and the expert group after the training in terms of en bloc resection, R0 resection, complication rate, endoscopic resection bleeding (ERB) score, muscularis propria injury (MPI) score, and resection time per unit area (P > 0.05).

CONCLUSION

The ETM-CP is effective for ESD training.

Modeling Haptic Interactions in Endoscopic Submucosal Dissection (ESD)

The ability to provide realistic haptic feedback is indispensable for virtual-reality (VR) based endoscopic colorectal surgery simulators. Despite its importance, force feedback is commonly simulated by simplified approximations with parameters manually tuned in preliminary evaluations due to the complexity of the dynamics of haptic interaction in colonoscopy interventions. Endoscopic submucosal dissection (ESD) is a particularly challenging intervention that requires advanced manual skills for endoscopic control. This work proposes a mechanical impedance model for haptic interactions in ESD formulated via an experimental methodology applied to endoscopic colorectal interventions in general. The developed model is shown to capture the variations in the interaction force during two operations performed at distinct locations on a porcine sample. Salient cues in the recorded haptic interaction data are presented, and changes in the impedance characteristics of the tool-tissue interaction between the steps of the operation are analyzed.

Cognitive task analysis and workload classification

Automation can be utilized to relieve humans of difficult and repetitive tasks in many domains, presenting the opportunity for safer and more efficient systems. This increase in automation has led to new supervisory roles for human operators where humans monitor feedback from autonomous systems and provide input when necessary. Optimizing these roles requires tools for evaluation of task complexity and resulting operator cognitive workload. Cognitive task analysis is a process for modeling the cognitive actions required of a human during a task. This work presents an enhanced version of this process: Cognitive Task Analysis and Workload Classification (CTAWC). The goal of developing CTAWC was to provide a standardized process to decompose cognitive tasks in enough depth to allow for precise identification of sources of cognitive workload. CTAWC has the following advantages over conventional CTA methodology:•Integrates standard terminology from existing taxonomies for task classification to describe expected operator cognitive workload during task performance.•Provides a framework to evaluate adequate cognitive depth when decomposing cognitive tasks.•Provides a standard model upon which to build an empirical study to evaluate task complexity.