Learning endoscopic submucosal dissection (ESD) is undertaken by experienced endoscopists in endoscopic mucosal resection and management of complications. Understanding the theoretical approach of the procedure and the cutting line is a prerequisite of performing it. The precise knife movements following the cutting line during incision, trimming and dissection takes time to master.

The European Society of Gastrointestinal Endoscopy (ESGE) recommends certain steps of the learning process: starting on animal models and further passing onto easier cases in patients, all these with expert supervision. Observation of experts directly or in live endoscopy meetings are recommended. Direct observation of the experts allow viewing and understanding the hand and finger movements during the specific ESD procedure phases (incision, trimming, dissection). Conversely, during live endoscopy meetings, one cannot see the hand and fingers movements of the operator. Using motion tracking smart-gloves, these fine movements may be visually broadcasted together with the endoscopic view during live meetings. There currently are no studies on motion tracking of hand and finger movements smart gloves in gastrointestinal endoscopy.

Broadcasting the ESD expert's hands and fingers movements using a motion tracking smart-glove during a live endoscopy event will increase the trainees ESD procedure speed. Concomitantly seeing the endoscopic view and the hand and fingers view, the trainee will establish a relationship between the hand and fingers movement and the effect on the dissected tissue. A faster practical "how to do it" formula will hopefully be acquired by the trainee.

Additional benefits are expected, as a faster trainee learning curve will diminish the carbon footprint of the endoscopic training process.

A prospective randomized study will be implemented to test the research hypothesis. Trainees will be divided in two groups, depending on their view during live ESD procedures performed by the experts: the study group [endoscopic view + hand motion view] versus the control group [only endoscopic view]. The experts endoscopists will demonstrate ESD procedures on an animal model. Afterwards, the trainee will perform, under supervision, an ESD procedure on the same animal model. Several parameters will be noted: speed of the procedure, the en-bloc or piece-meal resection, the R0 resection, presence of complications (perforation) and the satisfaction score of the trainee on a numerical visual scale.

Rationale.

ESD is difficult to learn. Learning is usually undertaken by already trained endoscopists, with experience in difficult polypectomy. Except marking, hemostasis and clip closure, the very precise distinctive ESD movements - incision, trimming and submucosal dissection are new hand gestures for someone starting this path.

After studying ESD strategy and tactics - where to start and continue ("when to cut") and what part of the lesion ("what to cut"), one needs to understand the cutting line ("where to cut"). This cutting line is to be followed precisely, in an extremely accurate manner during incision, trimming and actual submucosal dissection. Any millimetric deviation from this ideal line may and will result in lengthening or procedure failure in best case scenario and in iterative bleedings and perforation in worst case scenarios.

The ESGE learning curricula recommends that a proficient in EMR endoscopist should start supervised ESD training. Firstly, in animal models (at least 20 procedures with no perforation in the last 10 training cases and 80% R0 rate) and afterwards, supervised simpler cases on real patients [1]. Observing at least 20 ESD procedures performed by experts in tertiary referral centers as well as live conferences and meetings are encouraged.

Based on available evidence, current ESGE and ASGE guidelines for best practices of live endoscopy events do not find an increased harm for patients [2,3]. Moreover, in a study comparing the outcomes of ESD in a live event versus standard of care, the outcome numbers were non-inferior, and some were even slightly non significantly superior (en-bloc rates 100% vs. 87%, curative rates 84% vs. 71%, complication rates 5% vs. 13%, 5-year survival rates 70% vs. 65%) [4]. Nevertheless, both guidelines state that there is no current data supporting that attending live endoscopy events will improve ESD outcome in trainees.

Unfortunately, observing an ESD procedure during a live endoscopy event is not the same experience as being in the same room as the operator. The endoscopic screen and the verbal explanations may be there. Still, the exact hand movements by the operator will be missed. Viewing the expert's hands and fingers movements during such a complex procedure is of utmost importance.

A recent 2023 study evaluated the benefit of a live broadcasting GoPro action camera attached to the endoscopist head [5]. The supplementary doctor's eye-view video increased the trainees interest and understanding of the procedure. However, as the endoscopist gaze will be pointed to the endoscopy screen most of the time, the hand and finger gestures will not be GoPro broadcasted and live seen by trainees.

How to observe and analyze hand and finger movements during and ESD procedure? Hand gestures during colonoscopy were quantified in different studies assessing pressure and force by tactile pads, electrogoniometers, magnetic trackers and electromagnetic motion sensors [6-9]. These studies aimed to assess muscle strain and postures during colonoscopy and their different patterns in expert and novice operators.

Smart-gloves were proposed to measure kinesthetic and tactile feed-back, but also hand and finger pose and motion tracking [10]. Medical studies so far used hand motion tracking smart-gloves to quantify and/or monitor concomitant brain activation, hand joints stress, chest compressions during CPR, drawing coordination skills, surgical knot tying and post stroke hand grip rehabilitation [11-16]. Tracking hand and fingers motion during ESD may be possible as well using available commercial smart-gloves.

The ROKOKO smart-gloves use electro-magnetic field (EMF) sensors to capture precise hand and finger movements. It instantly broadcasts with 100 frame per second rate, without lag or latency. It may be integrated with all major 3D animation tools and game engines and is currently used, among others, by Walt Disney Studios, Universal Studios, Sony, Netflix, HBO, Electronic Arts, [17].

Study hypothesis.

Broadcasting the ESD expert's hands and fingers movements using a motion tracking smart-glove during a live endoscopy event will increase the trainees speed of the ESD procedure. It will increase the rate of en-bloc resection, the rates of curative resection and will decrease the rate of complications. While at distance, the trainee will be able to concomitantly see the two screens - the [endoscopic view] and the [hand and fingers view]. A relationship between the hand and fingers motions and the transmitted effect onto knife tip and further onto the lesion tissue will be better understood. A practical "how to do it" knowledge will be hopefully acquired by the trainee, faster.

Inclusion Criteria:

• ESD trainees with experience in EMR and difficult polypectomy

Exclusion Criteria:

• ESD trainees with previous significant experience in ESD on animal model
• ESD trainees with previous significant experience in ESD on patients