PART 1: MECHANICAL SIMULATORS
Background: Part 1
Gastrointestinal (GI) endoscopy is demanding, requiring integrative skills, both technical
and nontechnical (cognitive). For these reasons, training in GI endoscopy is challenging.
The increasing incorporation of simulators into the GI endoscopy training model represents
an important step forward in the practice of complex procedures in a controlled environment
avoiding the direct involvement of patients [1]
[2]. This is especially true for GI endoscopy trainees and is recommended in the Position
Statement of the European Society of Gastrointestinal Endoscopy (ESGE) on training
in basic GI endoscopy procedures [3].
Since the 1960 s [4], GI endoscopy simulators have been designed to mimic real-life procedures with the
purpose of allowing trainees to develop and improve their skills.
There are currently four classes of endoscopic simulators, each with its own advantages
and disadvantages: (I) mechanical simulators, (II) ex vivo and (III) in vivo animal
models, and (IV) computer-based (e. g. virtual reality [VR]) simulators. In addition,
some noncommercially available prototypes are also presented here to raise awareness
of the rapid progression of scientific research in this field.
The aim of this technical review is to provide an extensive and updated overview of
the currently commercially available simulators for training in GI endoscopic procedures
(both diagnostic and interventional), focusing on their technical features and applications,
and to provide a practical and easily consultable guide for trainers and trainees.
Methodology and development process
The ESGE Research Committee Chair (L.F.) and the ESGE Executive Committee, appointed
a leader (C.C.) for this technical review. They invited three more authors to be co-leaders
(I.B., J.J., I.H.) and a list of co-authors among the ESGE Research Committee members
to participate in this review. Two task forces were created to evaluate and report
on the different classes of simulators: one for mechanical simulators (task force
leaders, C.C. and I.B.) and one for in/ex vivo animal model simulators, VR, and prototypes
(leaders J.J., and I.H.).
The authors performed a systematic literature search on PubMed/MEDLINE, Scopus, and
the Cochrane Library to prepare an evidence-based, narrative review, identifying pertinent
clinical studies on the topic, published up to September 2024 as full-text or abstracts,
and restricted to English language. The following keywords were used for the search:
“endoscopy simulator,” “endoscopic simulator,” “endoscopy and simulator,” “colonoscopy
and simulator,” “gastroscopy and simulator,” “ERCP and simulator,” “endoscopic ultrasound
and simulator,” and “EUS and simulator,” amongst others.
The literature search was focused on randomized controlled trials (RCTs) and meta-analyses
of RCTs, but also encompassed observational studies, and case series. Pilot studies
were included if they addressed topics not covered in the RCTs. A database was created,
retrieving technical data from scientific publications and formal communications with
pertinent vendors. A significant effort was made to contact all the companies producing
the simulators in order to have additional and accurate information or to confirm
the available simulators and provide consent for reproduction of the simulator images.
All task force members were required to disclose potential financial and intellectual
conflicts of interest, which were addressed according to ESGE policies. Various online
meetings were held between the Research Committee Chair and the task force leaders
to discuss and resolve issues and finalize the draft by December 2024. The final draft
was reviewed by the ESGE Governing Board and two external reviewers, and after agreement
on a final version, the manuscript was submitted to the journal Endoscopy for publication in a two-part format: Part I on mechanical simulators and Part II
on in vivo/ex vivo models, VR, and prototypes. All authors agreed on the final revised
manuscript version.
Mechanical simulators: Overview
Mechanical simulators in GI endoscopy integrate synthetic soft (for the interior)
and hard (for the exterior) materials to replicate an organ’s anatomy. These mechanical
models are the most commonly used for simulation-based training in GI endoscopy. Usually,
insertion of a standard endoscope inside the simulator is enabled, which replicates
the standard endoscopic maneuvers. Many favorable properties characterize this class
of simulator: high fidelity in terms of haptic feedback, lower cost than other models,
and effectiveness for the initial phase of apprentice training. On the other hand,
as compared to animal models, mechanical models are generally less realistic, and
every additional endoscopic scenario requires creation of a different physical reproduction
[5]; however it should be highlighted that some recent and advanced mechanical simulators
offer highly realistic designs.
In the following text, all the available simulators are briefly described along with
the available evidence that supports their use. This is divided into three sections
according to the intended procedures: (a) endoluminal diagnostics ([Table 1]); (b) endoluminal interventions ([Table 2]); (c) biliary diagnostics and interventions ([Table 3]). For each simulator that is reviewed herein, and where available, a figure and
two tables (one for technical characteristics and one for related literature) are
included as Supplementary Material (available online-only).
Table 1
Mechanical endoluminal diagnostics simulators.
Simulator
|
Manufacturer
|
Target
|
Interventional Modules
|
Material
|
Weblink
|
Thompson Endoscopic Skill Trainer
|
EndoSim, USA
|
EGD
|
No
|
Silicone
|
https://endosim.com/product-page/thompson-endoscopic-skills-trainer-test
|
Left-Hand Trainer
|
Glück, Korea
|
EGD
|
No
|
Plastic
|
https://gluckmedical.com
|
EsophagoGastroDuodenoscopy (EGD) Simulator
|
Koken, Japan
|
EGD ERCP
|
No
|
Silicone
|
https://www.kokenmpc.co.jp/english/products/educational_medical_models/anatomical/lm-103.html
|
EGD Method Trainer (EGDS MT)
|
Anymedi, Korea
|
EGD
|
Yes; hemostasis and polypectomy
|
Silicone
|
https://www.anymedi.com/products/simulator
|
Upper GI Trainer
|
Chamberlain Group, USA
|
EGD
|
No
|
Silicone
|
https://www.thecgroup.com/product/upper-gi-trainer-2002/
|
Mikoto Gastrointestinal Endoscopy Model
|
R Zero (Fujifilm), Japan
|
EGD
|
No
|
Silicone
|
https://rzero.jp/mikoto/english.html
|
Medical Rising Star Ulcer-Type
|
Denka, Japan
|
Hemostasis
|
Yes; hemostasis
|
Plastic stomach with ulcer and vessels, connected to syringes
|
https://www.denka.co.jp/eng/pdf/corporate/thedenkaway/
|
Upper GI bleed Phantom
|
Nordic Phantoms, Denmark
|
Hemostasis
|
Yes; hemostasis
|
Plastic
|
https://nordic-phantoms.com/products/uppergi-bleed-phantom/
|
Colonoscope Training Simulator
|
Kyoto Kagaku Co., Japan
|
Colonosopy
|
No
|
Soft and hard resin
|
https://www.kyotokagaku.com/en/products_data/m40 /
|
Colonoscopy Trainer
|
Chamberlain Group, USA
|
Colonosopy
|
No
|
Plastic, silicone
|
https://www.thecgroup.com/product/colonoscopy-trainer-2003 /
|
Mikoto Colonoscopy Training Simulator
|
R Zero (Fujifilm-Olympus), Japan
|
Colonosopy
|
No
|
Silicone resin
|
https://rzero.jp/mikoto/english.html
|
Endoscopy Model System Trainer
|
Chamberlain Group, USA
|
EGD Colonosopy
|
Yes
|
Silicone
|
https://www.thecgroup.com/product/ems-trainer-2068 /
|
NKS 3 D colonoscopy simulator
|
Kyoto Kagaku, Japan
|
Colonosopy
|
No
|
Mechanical
|
https://www.kyotokagaku.com/en/products_data/mw24 /
|
Colonoscopy Lower GI Endoscopy Simulator Type II
|
Koken, Japan
|
Colonosopy
|
Yes
|
Silicone
|
https://www.kokenmpc.co.jp/english/products/educational_medical_models/anatomical/lm-107.html
|
Colonoscopy-Trainer LS90
|
Samed, Germany
|
Colonosopy
|
Yes;polypectomy
|
Plastic, silicone, tissue imitation
|
https://samed.dresden.de/en/ls90_en.php
|
EGD, esophagogastroduodenoscopy; NA, not available.
Table 2
Mechanical endoluminal intervention simulators.
Simulator
|
Manufacturer
|
Target
|
Interventional modules
|
Material
|
Weblink
|
Endoscopic Variceal Ligation Simulator
|
Glück, Korea
|
EVL
|
Yes
|
Plastic frame, silicone varix module
|
https://gluckmedical.com/25
|
EndoGel Training Model for ESD/POEM
|
Sunarrow, Japan
|
ESD POEM
|
Yes
|
Polyvinyl alcohol hydrogel
|
https://www.sunarrow.co.jp/en/endogel/
|
ESD Training Model
|
Koken, Japan
|
ESD
|
Yes
|
Silicone, polyurethane resin
|
https://www.kokenmpc.co.jp/english/products/educational_medical_models/
|
G-Master
|
Kotobuki Medical, Japan
|
ESD
|
Yes
|
Metal
|
https://www.kotobuki-medical.com/
|
Percutaneous Endoscopic Gastrostomy Simulator
|
Glück, Korea
|
PEG
|
Yes
|
Silicone, plastic module
|
https://gluckmedical.com/26
|
Freka Phant
|
Fresenius Kabi, Bad Homburg, Germany
|
PEG
|
Yes
|
Silicone, plastic
|
https://www.fresenius-kabi.com/de/pressemitteilungen
|
SimStar Family Simulators
|
Dr. Henke, Germany
|
EGD Colonoscopy EUS ERCP ESD
|
Yes
|
Silicone, 3D-printed parts
|
https://www.drhenke.com
|
EGD, esophagogastroduodenoscopy; ESD, endoscopic submucosal dissection; EUS, endoscopic
ultrasonography; EVL, endoscopic variceal ligation; PEG, percutaneous endoscopic gastrostomy;
POEM, peroral endoscopic myotomy; NA, not available.
ERCP, endoscopic retrograde cholangiopancreatography; NA, not available.
Endoluminal diagnostics: Upper GI tract
Thompson Endoscopic Skill Trainer
The Thompson Endoscopic Skill Trainer (TEST) (EndoSim LLC, Hudson, Massachusetts,
USA) is designed for practicing the five main skills required for the precise use
of an endoscope: retroflexion, torque, knob control, loop reduction, and navigation,
aiming to familiarize beginners with these maneuvers in both the upper and lower GI
tracts. A module with a light bulb attached to a small ring or silicone cap is mounted
inside the box. The model is easy to set up in any standard endoscopy suite, with
reusable components and minimal supervision.
Ou et al. reported that endoscopist performance using the TEST correlated well with
endoscopic metrics of performance (e. g., adenoma detection rate and cecal intubation
time), indicating its effectiveness in demonstrating competency [6]. The content validity index (CVI) of all five modules was 0.88 for realism, 1.00
for relevance, and 0.88 for representativeness, yielding a composite CVI of 0.92. Moreover,
when trainee performance was evaluated with two test administrators, the mean score
for all participants with proctor 1 was 297.6 and 308.1 with proctor 2 (P = 0.94), suggesting reproducibility and minimal error associated with test administration
[7] (Fig. 1s; Tables 1 s and 2 s; available online-only in Supplementary Material).
Left-Hand Trainer
The Left-Hand Trainer (Glück Medical, South Korea) is designed to train therapeutic
endoscopists to use their left hand for scope manipulation and control, so that the
right hand can independently and simultaneously operate any accessory in use. This
not only minimizes the need for an additional endoscopy assistant but also enhances
procedural efficiency by eliminating the need to detach the right hand to assist the
left. The model is designed to force trainees to only use their left hand to rotate
the scope and/or control the wheels on the knob, while simultaneously using their
right hand to control a biopsy forceps to perform a set of tasks (e. g., moving plastic
buttons inside the model) (Table 3 s).
Esophagogastroduodenoscopy simulator
The EGD (EsophagoGastroDuodenoscopy) Simulator (Koken Co., Ltd., Tokyo, Japan) is
a silicone frame resembling the upper GI tract (from the mouth to the duodenum), mounted
on a plastic panel to perform either transoral or transnasal EGD. To train for detecting
gastric lesions, a lesion resembling a gastric ulcer or early gastric cancer is placed
on the lesser curvature of the stomach. There is also an area where different simulated
polyps can be inserted. As a separately sold option, a polyp can be attached for practicing
resection and hemostasis using clipping [8]. In addition, there is a second ulcer located in the duodenum. Moreover, the EGD
simulator model also allows for endoscopic retrograde cholangiopancreatograhy (ERCP)
through the opening of the ampulla of Vater in the second part of the duodenum.
One study evaluated the training effect of this simulator both in novice and non-novice
endoscopists, and reported that 90.6 % of all participants, and specifically 92.9 %
of novice endoscopists, rated the simulator as helpful [9] (Tables 4 s and 5 s).
EsoGastroDuodenoscopy Method Trainer
The EsoGastroDuodenoscopy Method Trainer (EGD-MT; Anymedi Inc., Seoul, South Korea)
is produced using tridimensional (3 D) printing based on images obtained during computed
tomography (CT) scans, and silicone molding technologies; the printed elements are
glued together to replicate a realistic upper GI tract. The EGD-MT consists of two
training modules: one for basic endoscopy skills and a second called the Scope Handling
Trainer (SHT) module, with magnetically attached polyps allowing for forceps and snare
resection techniques. More recently, a modified version of this model was developed
to simulate basic hemostasis techniques (e. g., injection, through-the-scope clipping),
including the use of a waterjet pump.
Although no formal validation studies are available, the EGD-MT was assessed in two
studies, one for each model [10]
[11]). In both, novice and expert operators were timed while performing standardized
tasks and both models were graded using a 7-point Likert scale. The studies reported
that the model was realistic and that procedural duration significantly decreased
with repetition of the required endoscopic task, particularly in the novice operator
group (Tables 6 s and 7 s).
Upper GI Trainer
The Upper GI Trainer (Chamberlain Group LLC, Great Barrington, Massachusetts, USA)
is designed only for diagnostic esophagogastroduodenoscopy (EGD), including a head
and esophagus block, head cover, thorax cover, base, and stomach with an attached
duodenum, allowing endoscope passage. The esophagus is stable and scopeable, the pliable
stomach has rugae and a pylorus. Replaceable stomachs are available for repeated use.
Currently, no validation studies are available for this model (Table 8 s).
Mikoto Gastrointestinal Endoscopy Model
The Mikoto Gastrointestinal Endoscopy Model (R Zero Inc, Japan, provided by Fujifilm,
Tokyo, Japan) is designed for beginners to acquire basic gastroscopy skills, offering
an innovative sensory experience enhanced by a specially developed navigation function.
Four simulation modules are available, tailored to specific skill levels, and a voice
guidance and LED lighting provide intuitive support. Additionally, the simulator offers
immediate feedback and scoring to enhance skill acquisition. This simulator is currently
not available on the market, but it is expected soon. To date, no validation studies
have been conducted for this model (Table 9 s).
Medical Rising Star Ulcer-Type
Medical Rising Star Ulcer-Type (Denka, Tokyo, Japan) allows training in hemostasis
using hemostatic clips and graspers. It features a plastic model of the upper GI tract
with adjustable ulcer-like patches that simulate bleeding and allow for the use of
electrocautery. The system is quick to set up, reusable, transportable, and offers
variable complexity levels. However, it does not accurately simulate fibrotic ulcers
and has limitations in fluid accumulation [12]
[13]. A recent prospective study, including 50 gastroenterologists from Canada and Japan
recruited to participate in a simulation-based training program, showed that the primary
outcome, namely the hemostasis success rate of the trainees, significantly increased
after instruction (64 % vs. 86 %, P < 0.05). This simulator was demonstrated to be a potentially valuable tool for improving
technical skills and confidence [13] (Table 10 s, 11 s). Currently, no validation studies are available for this model.
UpperGI Bleed Phantom
The UpperGI Bleed Phantom (Nordic Phantoms, Odense, Denmark) model is designed to
simulate treatment of upper GI bleeding (e. g., clipping, injection therapy, band
ligation, and esophageal stent or balloon tamponade placement). Made from silicone,
it closely mimics the texture and responsiveness of human tissue. It includes internal
channels and an electrically driven fluid system that mimics active bleeding, with
a custom blood solution replicating real blood’s viscosity, color, and flow characteristics
under pressure. The model features exchangeable inserts, allowing users to practice
managing various bleeding sources such as ulcers, varices, or neoplasms. Due to its
durable materials, the system is designed for easy cleaning and reuse, ensuring long-term
functionality and maintaining hygiene standards (Fig. 2s; Table 12 s). No validation studies are currently available for this model.
Endoluminal diagnostics: Lower GI tract
Colonoscope Training Simulator
The Colonoscope Training Simulator (CTS; Kyoto Kagaku Co., Japan) features a 3 D resin
model of the colon based on CT images. The model simulates colonoscope insertion and
manipulation using six different configurations mimicking different difficulty levels.
The incorporation of an adjustable anal sphincter pump provides an airtight model
configuration that allows for insufflation and suction techniques. The sigmoid colon
can be preset to have any of three common anatomic morphologies (alpha, long alpha,
or N loop), and three patient positions can be employed (supine, left lateral, and
right lateral). The CTS also allows for the provision of manual abdominal compression
training, using a membrane on top of the colon model to simulate the anterior abdominal
wall. Furthermore, the model can be combined with other teaching tools such as the
Scope Guide (Olympus), thus enhancing the training experience.
The construct validity of this model was evaluated [14], demonstrating that the CTS can discriminate among operators’ expertise based on
performance outcome measurements. Furthermore, a comparison study showed that the
CTS was considered to be more realistic compared with the GI Mentor II (VR) model
[15]. Despite these encouraging results [16], studies of trainee performance in real-life cases showed mixed results for the
utility of the CTS [17]
[18].
The more commonly sold version of this colonoscopy simulator is the CTS M40, made
of mixed soft/hard resin, and used in different studies to evaluate parameters such
as targeted biopsy [19], monitoring of endoscopic competence [20], and learning curve [21] (Figs. 3As, 3Bs; Tables 13 s, 14 s).
Colonoscopy Trainer
The Colonoscopy Trainer (Chamberlain Group LLC, Great Barrington, Massachusetts, USA)
is designed for training novice endoscopists on basic colonoscopy insertion and intubation
techniques. The interior of the model is designed to replicate the colorectal structure
and allows the insertion of a single stricture and a fixed number of polyps. The plastic
exterior model encapsulates the colon in a rigid foam material, thus supporting the
colon anatomy [5]. It is reasonably priced and requires no significant preparation or setup. However,
this model does not provide any interventional training modules or effects of suction/insufflation
(Table 15 s).
Mikoto Colonoscopy Training Simulator
The Mikoto Colonoscopy Training Simulator (R Zero Inc, Japan, distributed by Fujifilm,
Tokyo, Japan, and Olympus Corporation, Tokyo, Japan), is known for its anatomical
realism and real-time haptic feedback, aiding in diagnostic procedures including polyp
detection. The crafted organ is replaceable in the case of perforation, though at
a high cost. External cameras monitor the endoscopist’s position and movements, and
recorded videos can be utilized for objective feedback. This model features motors
for positional changes and high fidelity pressure and optical sensors, to simulate
patient pain. Suitable for all skill levels (with options for different levels of
difficulty), the model offers objective performance metrics with automatic scoring
for self-learning. Its high cost is influenced by factors such as customization options,
service packages, and regional pricing differences [22]
[23] (Fig. 4s; Table 16 s).
Endoscopy Model System Trainer
The Endoscopy Model System (EMS) Trainer (Chamberlain Group LLC, Great Barrington,
Massachusetts, USA) provides simulated access to the entire GI tract within a compact
platform appropriate for multiple GI endoscopy procedures. Silicone models of the
esophagus, stomach and colon are combined into one framework and, after each tissue
element has been inserted into the model, many endoscopic techniques can be performed
(e. g. biopsy, colonic polyp snaring, clipping for bleeding gastric ulcer or colonic
post-polypectomy hemostasis or perforation, and stenting for esophageal, pyloric,
and duodenal strictures).
This model is considered to be useful for teaching endoscopy trainees/novices specific
endoscopic techniques (Table 17 s).
Noda–Kitada–Suzuki 3 D colonoscopy simulator
The Noda–Kitada–Suzuki (NKS) 3 D colonoscopy simulator (Kyoto Kagaku Co., Ltd, Japan),
includes a skeleton body, abdominal membrane, colon–rectum tube, and other accessories.
The device, based on CT colonography data, features a transparent tube with a silicone
large intestine for visual inspection. It aids in cecal intubation and loop reduction,
with adjustable colon anatomic morphologies (Table 18 s).
Colonoscopy Lower GI Endoscopy Simulator Type II
The Colonoscopy Lower GI Endoscopy Simulator Type II (Koken Co., Ltd, Japan) is made
with a special silicone rubber that simulates a realistic feel. The model includes
four colon tubes joined by three connectors and a virtual peritoneal membrane. It
offers the following options: simulated polyps and laterally spreading tumors for
observation or polypectomy, clipping technique for hemostasis practice, and an optional
“small intestine” for enteroscopy training with adjustable difficulty. The small intestine
is 120 cm long with internal scale markings (Table 19 s).
Colonoscopy-Trainer LS90
The Colonoscopy-Trainer LS90 (SAMED GmbH, Dresden, Germany) is a mechanical model
consisting of a plastic phantom (body with bracket), a silicone colon, and an imitation
of the buttocks. The model can be used to perform colonoscopy in the lateral or supine
patient position, for both diagnostic and therapeutic exercises. There is the possibility
to choose among three colon “tins,” each replicating a colonic region with different
scenarios: (i) a diagnostic model for detection of polyps and Crohn’s disease (silicone);
(ii) a diagnostic model for biopsy of carcinoma and polyps (silicone); and (iii) a
therapeutic model for endoscopic resection of pediculated and flat polyps (tissue
imitation, storable for 6 months) (Fig. 5 s, Table 20 s).
Endoluminal intervention simulators
Endoscopic Variceal Ligation Simulator
The Endoscopic Variceal Ligation (EVL) simulator (Glück Medical Co., South Korea)
is made of a plastic esophagus-shaped frame and a silicone varix core containing three
columns of varices. This allows for multiple attempts at band ligation or the simultaneous
training of multiple endoscopists on the same module. The silicone core is intended
to provide a degree of anatomic realism and feedback as it is designed to be ligated
if the procedure is done correctly, and it also adapts to the degree of suction (i. e.,
failure of ligation if inadequate suction). The device does not contain the band ligation
kit, which needs to be provided separately (Table 21 s).
EndoGel Training Model for endoscopic submucosal dissection (ESD) and peroral endoscopic
myotomy (POEM)
The Endogel Training Model (ETM; Sunarrow Co., Ltd, Japan, provided by Fujifilm, Tokyo,
Japan) consists of a stainless steel container filled with stacked, multilayer polyvinyl
alcohol hydrogel plates that replicate the physical properties of each layer of the
GI tract, allowing trainees to perform ESD or POEM procedures [8]
[24]. The main advantages of the ETM include its reproducibility, realistic feedback
and eco-friendliness (human-use endoscopes are used in nondedicated rooms without
the risk of contamination with animal tissue).
A study of 28 trainees in endoscopy [25] reported a satisfaction and feasibility rate of 100 % and 96.4 %, respectively.
Other studies have reported good reproducibility and a close simulation to real-life
endoscopy experience [26]
[27], as well as showing improvement in complete resection rates after three ESD training
sessions and a decreased perforation rate after four training sessions [28]. A review article [29] described the ETM as most effective when combined with personalized one-on-one instruction,
recommending approximately three training sessions to gain proficiency, after which
it was advisable to proceed to live porcine ESD training (Fig. 6s; Tables 22 s and 23 s).
ESD training model
The ESD Training Model (Koken Co., Ltd, Japan) combines a mechanical simulator with
an attached dissected pig stomach. An aluminum outer case contains a stomach-shaped
model made from silicone rubber and polyurethane resin, aiding in realism, and the
esophagogastric junction is made of a soft resin material. The animal-based tissue
can be fitted to different parts of the stomach using a stainless steel plate to which
electrodes can be attached, allowing for the use of diathermy during ESD training.
This model gives the opportunity to simulate ESD in different anatomical parts of
the stomach which pose distinctive technical challenges. However, ex vivo animal tissue
preparation is required for this model, which is a limitation (Table 24 s).
G-Master
The G-Master (Kotobuki Medical Inc, Saitama, Japan) is designed for gastric ESD training
and consists primarily of a konjac flour sheet that simulates the mucous membrane
(composed of three layers: mucosal, submucosal, and muscular), supported by a complex
metal chassis (width 635 mm × diameter 300 mm × height 310 mm). The model includes
a plastic tube resembling the esophagus, ending in a cardiac-like section that is
adjustable in three spatial directions, and transitioning into a plastic spatula to
mimic the stomach's greater curvature. The flour sheet is fixed with adjustable tension
to simulate different stomach distensions. The model has 9 adjustable components,
allowing the mucous membrane to be positioned in 11 locations across anterior and
posterior walls and lesser and greater curvatures.
A validation study involving 8 expert endoscopists performing ESD on 33 lesions in
3–5 locations [30] rated the simulator highly for realism, with no perforations recorded. A recent
multicenter study compared ESD performed by 15 novice trainees, divided into G-Master-trained
and nontrained groups [31]; the trained group showed faster ESD procedural speed and a trend towards fewer
perforations and less intervention by experts. Kotobuki Medical recently launched
a G-Master colorectal ESD version, with a colon-like tube and a dedicated traction
sponge for practicing specific ESD techniques (Table 25 s).
Percutaneous Endoscopic Gastrostomy (PEG) Simulator
The PEG simulator (Glück Co., Korea) is made using 3 D printing, aiming to simulate
PEG through the abdominal and gastric walls by placement of a silicone element, designed
to mimic these structures, into the opening of a plastic stomach model. The model
allows PEG training with both push and pull techniques and is reusable. Na et al.
[32] reported that use of the PEG simulator reduced procedural time and mean procedure
difficulty scores for beginners, while increasing the mean self-evaluation scores.
The nonexpert group reported an improvement in skill score of 6.3. These results were
subsequently confirmed by others [33], demonstrating a significant improvement in PEG technical skills and self-confidence
for beginners (Table 26 s).
Freka Phant
The Freka Phant (Fresenius Kabi, Bad Homburg, Germany) is a mechanical simulator that
allows the endoscopist to practice PEG by inserting an endoscope into a plastic box
and puncturing skin patches. The model comprises latex and natural rubber-free materials
and can be installed with two different skin diameter patches. Multiple tasks are
available, such as pull or push technique, gastropexy, changing of exchange systems
(balloon probes), measurement of stoma length (stoma length gauge), and wound care.
This simulator can be useful for training novice endoscopists in the basic skills
of PEG placement; however, other integrated technical skills of EGD cannot be simulated
(Table 27 s).
SimStar Family Simulators
This group (Dr. Henke, Germany, Electronic Associates, Inc) of endoscopy simulators
includes many simulators designed for upper and lower GI procedures, featuring realistic
anatomy with different elements made of H-Flex material inserted for repeated use.
The SimStar Gastro Upper GI simulator is designed for EGD, offering various diagnostic
and interventional scenarios, and includes a blood perfusion system oriented to hemostasis
techniques. The model supports several technical maneuvers including polypectomy,
mucosal biopsy, variceal band ligation, stent placement (esophagus, stomach, duodenum),
as well as the use of injection, clip, and loop systems for hemostasis. Medtronic
Inc supports simulated bleeding in this model with a water-filled syringe; the “bleeding”
has to be stopped using its topical hemostatic agent, Nexpowder.
This group of simulators also offers several options for training in colonoscopy (diagnostic
and interventional), ERCP (basic and advanced maneuvers), and endoscopic ultrasound
(EUS) with the facility to practice puncture technique. The simulator is reported
to provide real-time feedback, good handling, and affordability (Fig. 7s; Table 28 s).
Biliary diagnostics and intervention simulators
Biliary Endoscopy Trainer and the ERCP Trainer
The Biliary Endoscopy Trainer (Chamberlain Group LLC, Great Barrington, Massachusetts,
USA) reproduces the biliary and pancreatic system with insertion of replaceable strictures,
to provide hands-on training for and tissue biopsy of the common bile duct (CBD).
This simulator is made of silicone and does not reproduce the full anatomy of the
upper GI tract; in fact to reach the biliary tree the scope is passed through a system
of multiple straps to keep it stable. It allows only for the realistic deployment
of devices inside the CBD.
The ERCP Trainer (Chamberlain Group LLC) represents a more advanced version in which
the biliary tree is placed in a box, reachable through a long tube (simulating the
passage of a scope through esophagus, stomach, and duodenum). The ERCP trainer can
simulate both the lateral and prone positions. Also, two anatomical covers, one clear
for direct visualization and one opaque for endoscopic viewing, are provided. Fluid
injection is allowed through a dedicated port.
Katanuma et al. slightly modified this model to develop a dry model for endoscopic
sphincterotomy and needle-knife precut sphincterotomy, creating a simulated papilla
with a piece of rolled uncured ham. The investigators enrolled 21 endoscopists in
a hands-on training study using this model; sphincterotomy was successful in 97 %
and precut in 100 %, with questionnaire median scores for realism of 7 and 8, respectively,
on a scale of 1 to 10 [34] (Table 29 s).
Boskoski-Costamagna ERCP trainer
The initial prototype of the Boskoski–Costamagna ERCP trainer (BCT; Cook Medical,
Limerick, Ireland) was composed of a metal and plastic frame simulating the upper
GI tract and a latex papilla connected to biliary and pancreatic ducts [35]. This initial model was validated for cannulation in various anatomical scenarios
and also for biliary stenting and stone extraction [36]
[37]. The model is not commercialized yet, but it can be accessed through Cook Medical
representatives.
To increase its technical realism, a subsequent version was designed with a synthetic
papilla model [38], and later with the option to use ex vivo chicken heart explants. This updated model
was validated for teaching conventional sphincterotomy, precut, and ampullectomy [39]. Furthermore, this ERCP trainer was assessed in several studies. The first RCT,
in a preclinical setting, demonstrated an improvement in cannulation times for endoscopy
trainees using an innovative “motion-training” exercise on the BCT model. A subsequent
international observational multicentric study demonstrated the improvement of early
cannulation rates in trainees exposed to the BCT compared to those receiving standard
ERCP training [40]
[41]. Moreover, a large international RCT demonstrated that overall competence in ERCP
(assessed by a validated tool) was significantly higher in the ERCP simulator-trained
group compared to controls [42] (Fig. 8s; Tables 30 s and 31 s).
CompactERCP Trainer
The CompactERCP Trainer (EndoSim LLC, Bolton, Massachusetts, USA) is designed for
practicing ERCP techniques including cannulation of the bile and pancreatic ducts,
sphincterotomy, stone extraction, biopsies, and stent placement and removal. The simulator
features realistic duct anatomy and provides real-time feedback to improve precision
and manipulation skills. Currently, no published validation data or additional detailed
model information are available (Table 32 s).
Summary and Conclusions: Part 1
Mechanical simulators for GI endoscopic procedures (both diagnostic and therapeutic)
provide a significant advantage in endoscopic training by offering a safe and controlled
environment for practice. The simulator models offered on the market are extensive
apart from for EUS, where availability is very limited with only one model offering
this facility, and double-balloon enteroscopy for which there is no availability.
Expensive models are often more realistic and complex in functionality, while other,
more affordable, simulators may be simpler and less suitable for advanced endoscopy
training. Despite the abundance of available mechanical simulators and their assumed
favorable impact on endoscopic training, validation studies demonstrating effectiveness
remain lacking for most of the models.
To the best of our knowledge, no comprehensive comparative studies have been conducted
among the various endoscopic simulators; therefore, the choice of a specific simulator
over another may be multifactorial, including personal preferences and available budget,
and also ethical considerations, particularly in relation to in vivo models and the
regulations set by relevant authorities.
PART 2: ANIMAL/VIRTUAL REALITY SIMULATORS AND PROTOTYPES
Background: Part 2
In this second and final part of the ESGE Technical and Technology Review dedicated
to GI endoscopy simulators and training models, an updated overview of the available
ex vivo, in vivo, and virtual reality (VR) simulators is provided. We also include
a section dedicated to simulator prototypes currently under development but not yet
commercially available. The aim of this review is to provide a practical, updated
and easily consultable guide for trainers and trainees in GI endoscopy who wish to
incorporate endoscopy simulators and training models into their daily practice.
Methodology and development process
The methodology and development process has already been reported in Part 1 of this Technical Review. All authors agreed on the final revised versions.
Ex vivo simulators
Ex vivo models are a cornerstone of flexible GI endoscopy simulation. Their advantages
include their widespread availability at reasonable prices via specialist companies
or even directly through an organization with a regulated slaughterhouse. From a technical
point of view, ex vivo models mimic the human anatomy, offer a layered structure identical
to that of humans, provide good electrical conduction capacity and realistic haptic
feedback. These models can be used as an attachment to plastic models offered by manufacturers
or made by hand. Moreover, ex vivo models can be preserved frozen (requiring a dedicated
storage freezer) for use on demand in simulation units after being thawed in water
[43]
[44].
The major limitation is the need for endoscopes dedicated to animal use only, to ensure
compatibility and to minimize damage to the model and to prevent wear and tear of
the clinical scopes. On the other hand, they are more suitable for repeated use without
the stringent sterilization requirements of clinical instruments. Additional limitations
to their use relate to anatomical differences compared to humans (see In vivo simulators) even if this is minimized by the use only of the desired lumen, an unpleasant odour
after a few hours of training, and ethical concerns. The latter are slightly less
significant than in the in vivo situation, as the GI samples are supposed to be obtained
from abattoirs where the animals are killed for meat production.
There follows an outline of available ex vivo GI endoscopy simulators ([Table 4]) along with brief technical descriptions.
DBE, double-balloon enteroscopy; EGD, esophagogastroduodenoscopy; EMR, endoscopic
mucosal resection; ERCP, endoscopic retrograde cholangiopancreatography; EUS, endoscopic
ultrasonography; NA, not available.
Erlangen Active Simulator for Interventional Endoscopy (EASIE) series (Erlangen Endo-Trainer):
Erlangen compactEASIE/EASIE-R (compact version) to EASIE-R4
The Erlangen team, pioneers in ex vivo simulator development since the 1990 s, introduced
a range of models, notably the EASIE, commercially available as the Erlangen Endo-Trainer.
Since 1997, EASIE [44]
[45] and its updated versions (EASIE-R, EASIE-R1 to EASIE-R4; EndoSim LLC, Hudson, Massachusetts,
USA) [5]
[23] have utilized ex vivo porcine organs that provide realistic haptic feedback. These
devices were subsequently developed with improved plastic frames to better mimic human
anatomy, and were even endowed with ex vivo esophagus and stomach. EASIE was the first
model to simulate arterial bleeding accurately, using a perfusion device equipped
with an adaptable box and a stop-valve system. This regulates the blood circulation,
thanks to an electric pump that simulates the heart rate of a patient, and the device
is easily controlled by an assistant.
Over time, these models have expanded to allow a wide range of endoscopic procedures,
from basic to advanced techniques, such as polypectomy, endoscopic mucosal resection
(EMR), endoscopic submucosal dissection (ESD), double-balloon enteroscopy, and luminal
stenting. The latest version, the EASIE-R4, focuses on upper GI tract training and
features an improved torso-shaped tray for specimen support, allowing secure positioning.
It includes new endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic
ultrasound (EUS) modules, such as an insert for biliary ducts that enables fluoroscopy
simulation without the use of X-rays, and a model for EUS-guided direct biliary access
using ultrasound to simulate access to an artificially dilated bile duct [23].
A new EASIE-R5 will soon be launched. This has a mannequin head, with the oropharyngeal
section being ex vivo porcine tissue that allows the specimen to be submerged in water,
and that can be heated to body temperature, improving the conductivity of electrocautery
for ESD and peroral endoscopic myotomy (POEM).
The EASIE simulators have been extensively validated as effective tools for GI endoscopy
training, significantly enhancing trainees’ skills. Hochberger et al. conducted a
RCT [46] comparing standard clinical training with intensive training using the compact EASIE
model. Among 28 randomized GI trainees, compared to the control group, those trained
with the simulator showed significant improvement in all evaluated endoscopic techniques.
Similarly, Maiss et al. evaluated a 1-day training course using the compact EASIE,
revealing significant skill enhancements among GI fellows [47]. Following a successful pilot project in the US, a similar program was implemented
in France, confirming the better performance of simulator-trained fellows [48]
[49]. Its usefulness has also been expanded to “train the trainer” sessions for endoscopists,
resulting in newly trained tutors achieving outcomes comparable to those of expert-led
training sessions [50].
Workshops using visceral organ packages also validated training for push-and-pull
enteroscopy and small-bowel insertion measurement, showing accurate results [51].
In comparison with other ERCP teaching models, the Erlangen Endo-Trainer’s pilot study
demonstrated its feasibility for simulating ERCP [52], and found that porcine organ models offered greater realism and utility [53].
The latest EASIE-R simulator, developed for EUS, has shown effectiveness in improving
GI fellows’ abilities to recognize anatomical structures and perform fine-needle aspiration
(FNA), validating the simulator’s role in structured endoscopic training programs
[54] (Fig. 9 s, Fig. 10s; Tables 33 s, 34 s).
Colo-EASIE/Colo-EASIE2
Colo-EASIE and its updated version Colo-EASIE2 (Erlangen team; EndoSim LLC, Hudson,
Massachusetts, USA) were developed for proctoscopy, sigmoidoscopy, and colonoscopy
training. Utilizing a plastic platform and ex vivo bovine or porcine colon specimens,
the model offers realistic training for procedures including polypectomy, EMR/ESD,
and GI bleeding [23]. The platform can rotate to simulate patient positioning, though it has limitations
in scope advancement methods. Despite positive feedback from early users, no formal
validation or comparative studies have been conducted, limiting scientific support
for its training effectiveness (Fig. 11s; Table 35 s).
EUS RK Phantom
The EUS RK Phantom (Dr. Koji Matsuda) is a modified EASIE model specifically for EUS
training, using a pig stomach placed in a silicone case, surrounded by grapes (simulating
lymph nodes or cystic lesions) and plastic tubes (mimicking the aorta and trachea)
[55]. The setup is immersed in gelatin for acoustic coupling. Preparation is labor-intensive
(about 6 hours), but the model can be stored for 2–3 days in a refrigerator. It offers
a realistic environment for basic EUS training and was widely used in training sessions
in the early 2000 s. Experts rated it favorably for visualization and manipulation,
though it was considered intermediate in realism and ease of use [56] (Table 36 s).
Neo-Papilla
The Neo-Papilla (EndoSim LLC, Hudson, Massachusetts, USA), used in the EASIE simulator,
offers a realistic alternative for ERCP training (sphincterotomy, post-sphincterotomy
bleeding, and stent placement) by using modified porcine tissue and 15–20 chicken-heart
simulated papillae per model, enabling performance of multiple procedures. Evaluated
initially by 9 experts, the Neo-Papilla was rated highly for realism and usefulness,
particularly for basic ERCP skills, with scores comparable or superior to VR and live
animal models [57]. Despite its advantages, such as reduced costs and no need for fluoroscopy, this
model requires time for preparation and tissue disposal (Tables 37 s, 38 s).
Endo X Trainer
The Endo X Trainer (Medical Innovations International Inc., Rochester, Minnesota,
US) is a plastic/ex vivo model for EGD, colonoscopy, and ERCP training [58], including therapeutic procedures (bleeding, polypectomy). Despite limited face
validity, one study has reported its content, construct, and criterion validity [59]
[60]. The model is lightweight and portable, characterized by a realistic mimicking of
the endoscopic mucosal appearance, perception of scope movements, and evaluation of
cecal intubation time (Tables 39 s, 40 s).
DeLegge EndoExpert Tray
The DeLegge EndoExpert Tray (DeLegge Medical LLC, Awendaw, California, US) is a composite
plastic/ex vivo simulator for training in EGD, colonoscopy, and ERCP (with interventional
modules for bleeding and polypectomy), using ex vivo porcine organs in a portable
tray. This model is available in the USA and Canada [58] (Table 41 s).
In vivo simulators
In vivo simulators for training in GI endoscopy involve the use of anesthetized live
animals, primarily pigs due to their similarity to human GI tract anatomy, especially
pigs weighing over 30 kg [61]. These models provide the most realistic simulation experience, replicating haptic
feedback, secretions, respiratory movements, and peristalsis, which are nearly identical
to those encountered in humans. This realism makes these in vivo animal models valuable
for training in advanced endoscopic procedures and safely managing intraprocedural
adverse events.
However, there are some anatomical differences between pigs and humans, such as the
presence of a diverticulum in the gastric cardia, a large amount of submucosal fat
in the colonic wall, and the lack of abdominal wall fixation of the proximal colon.
This is particularly relevant for ERCP and EUS because the porcine pancreaticobiliary
anatomy differs significantly (pancreatic duct and bile duct are separated), making
bile duct cannulation more challenging [62]
[63]. Despite these limitations, in vivo porcine models have proven effective for training
in ESD, with studies showing improvement in resection skills and a decrease in adverse
events through repeated practice [64]
[65]
[66].
The use of in vivo models is, however, limited by significant logistical, financial,
and ethical challenges. Setting up these models requires substantial investment in
infrastructure, animal lab facilities, and specialized equipment, including dedicated
“animal-only” use endoscopes. The animals used require extensive preparation, such
as dietary restrictions, fasting, and bowel cleansing before procedures. General anesthesia,
endotracheal intubation, and mechanical ventilation are necessary during training,
requiring the presence of a veterinarian. Furthermore, animals are usually euthanized
post-training, raising ethical concerns.
Ethical committees must approve the use of live animals, with an emphasis on balancing
animal welfare against the benefits of training. The increasing availability of ex
vivo alternatives further intensifies these ethical concerns. Additionally, certain
interventions such as sphincterotomy, cannot be repeated on the same animal, thereby
limiting the practical utility of live models compared to reusable options. Finally,
the cost of facilities authorized for animal experimentation is significant.
Given these constraints, the use of in vivo animal models remains restricted and is
generally recommended for advanced stages of training (e. g. ESD or therapeutic EUS).
Economic, ethical, and logistical demands mean that in vivo models are unlikely to
become a widespread option for basic GI endoscopic training.
Virtual reality (VR) simulators
VR simulators ([Table 5]) are contemporary systems using computer modeling to simulate the endoscopy experience.
A three-dimensional (3 D) model of the GI tract, generated through a combination of
hardware components and software functionalities, is investigated using a standard
endoscope as controller. Upon entrance of the endoscope into the machine, the user
is transferred to a virtual environment that responds to the user’s endoscopic movements
in real time for practicing multiple endoscopic scenarios. This is while receiving
haptic, audio, and visual feedback regarding his/her performance according to objective
indices that measure endoscopic competency [5]
[67]
[68].
Table 5
Virtual reality (VR) simulator models.
Simulator
|
Manufacturer
|
Target
|
Material
|
Ease of use
|
Link
|
CAE Endo VR
|
CAE Healthcare, Montreal, Quebec, Canada
|
EGD Colonoscopy ERCP Biopsy Polypectomy Bleeding
|
Silicone/2 monitors/cart/Integrated keyboard
|
Easy
|
https://www.caehealth-care.com/media/files/User_Guides/EndoVR-User-Guide.pdf
|
Endo Suite GI Mentor
|
Simbionix, later acquired by Surgical Science
|
EGD Colonoscopy, ERCP EUS Bleeding EMR ESD
|
Silicone/1 monitor/cart/Integrated keyboard
|
Easy
|
https://surgicalscience.com/simulators/gi-mentor/
|
ViGaTu simulator
|
University Hospital Wurzburg, Open Source Project
|
Multiple
|
VR
|
Unclear
|
https://github.com/virtual-gastro-tutor/vigatu
|
EndoSim
|
Surgical Science, Sweden
|
EGD Colonoscopy ERCP
|
VR
|
Easy
|
https://surgicalscience.com/simulators/endosim/
|
EndoVision Standard
|
MedVision
|
EGD Colonoscopy Bronchoscopy
|
VR
|
Easy
|
https://www.medvisiongroup.com/endovision.html
|
CLA 4/5–5/4
|
Coburger Lehrmittelanstalt, CLA, Coburg, Germany
|
EGD Colonoscopy Bronchoscopy
|
VR
|
Unclear
|
NA
|
EGD, esophagogastroduodenoscopy; ERCP, endoscopic retrograde cholangiopancreatography;
EMR, endoscopic mucosal resection; ESD, endoscopic submucosal dissection; NA, not
available; VR virtual reality.
Furthermore, unlike ex vivo animal models, these VR simulators do not require maintenance
in the form of replacement tissue and have the potential to include built-in training
software programs that could prove a cost-effective way to provide early training
without requiring the time of an endoscopy trainer.
CAE EndoVR
The CAE Healthcare VR simulator (CAE Healthcare, Montreal, Quebec, Canada; previously
called the AccuTouch Endoscopy Simulator, and redesigned in 2012) is a sophisticated
platform with a specialized endoscope inserted into the simulator, a display monitor,
and an endoscopic interface device [69]. The system mechanics enable haptic feedback to reproduce the sensation of endoscope
looping and resistance, along with a computer-generated voice simulating patient discomfort.
An additional multimedia function is available, where didactic video clips of experienced
endoscopists or an anatomy–pathology atlas can be accessed. CAE allows performance
of EGD, colonoscopy, and ERCP as well as polypectomy, biopsy, and hemostasis. This
VR model offers an accurate replication of real-life endoscopy experience as the patient’s
parameters are virtually displayed (i. e., vital signs, electrocardiogram, oxygen
saturation) and are subject to change according to the performed endoscopic maneuvers.
Trainees are required to manage sedation during endoscopy without compromising the
patient’s oxygen saturation.
Preliminary studies [70] evaluated the construct validity of the sigmoidoscopy and colonoscopy simulator
[71]
[72], followed by results from RCT [73] and prospective studies [74]
[75] which were less promising. Subsequently, additional RCTs reported a significant
increase in completion rate (52 % vs. 19 %, P = 0.001) and reduction of both procedure time and patient discomfort among trainees
who had already achieved a high level of performance in the simulator compared to
controls [76]. This achievement was enhanced by the presence of a supervisor [77]; this role in a training program has been extensively underlined [77]
[78]
[79]. Finally, in a study examining the ERCP module, the performance of apprentice fellows
and faculty members was compared, with the total procedure time being significantly
shorter in the expert group (444 vs. 617 seconds, P = 0.03) [80] (Tables 42 s, 43 s).
ENDO Suite-GI Mentor
The ENDO Suite-GI Mentor (Simbionix Corp., later acquired by Surgical Science, Sweden),
which represents the newest version of GI Mentor II, offers the widest variety of
GI endoscopy tasks available, allowing basic EGD and colonoscopy as well as advanced
procedures (EMR/ESD, hemostasis), with the availability of modules for EUS and ERCP.
This simulator features over 120 different tasks, a pain indicator and endoscope locator
are available during the simulation, and the system guides the user step by step in
learning the deconstructed skills (i. e., endoscopic navigation, mucosal inspection,
and loop reduction). To enhance realism, the endoscope is inserted through an orifice
into the model that is in the left lateral position and, while advancing, the system
displays on the screen credible visual and audible feedback based on endoscope manipulation.
Training in ERCP uses a split screen (endoscopic and fluoroscopic views), different
patient cases with diverse anatomy, and performance of therapeutic procedures (sphincterotomy,
stone extraction, stent placement, etc.). A portable edition, known as the GI Mentor
Express, is also available, consisting of a box where the endoscope is inserted while
a laptop computer can be used as a screen.
Data from RCTs suggest that, compared with nonsimulator-trained fellows, training
with VR before conventional endoscopy provides benefit in procedure completion time
(239 vs. 310 seconds, P < 0.0001) and technical accuracy (85 % vs. 72 %, P < 0.01) [81]
[82]. There is strong evidence on its usefulness from RCT and prospective cohort studies,
regarding colonoscopy [83]
[84] and ERCP [85]. In a recent study assessing the construct validity of virtual ERCP using the GI
Mentor II, the time to visualize the papilla and achieve deep cannulation was significantly
shorter for experts (both P < 0.05), especially in the management of cystic leakage [86]. Data regarding GI Mentor’s EUS module remain scant, with evidence suggesting that
it surpasses other types of simulators in terms of usefulness and realism, but there
remain limitations regarding the VR EUS-FNA training mode [55] (Fig. 12s; Tables 44 s, 45 s).
ViGaTu simulator
The Immersive Virtual Reality Endoscopy Suite (ViGaTu, University Hospital Wurzburg,
Open Source Project, Germany) was developed as a collaborative venture between physicians
and nurses specializing in endoscopy, media educators, and computer scientists. The
Meta Quest 2 system (Meta Platforms Inc., Menlo Park, California, United States) was
used to present the simulation which consists of a head-mounted display and two handheld
manual controllers (not a dedicated endoscope). The virtual environment was created
using Unity 3 D (Unity Technologies, San Francisco, California, United States) with
the 3 D elements designed in collaboration with ThreeDee (ThreeDee GmbH, Munich, Germany).
The framework of ViGaTu is open source and can be downloaded.
The ViGaTu project aims to enable both physicians and nonphysician specialists to
gain training in peri-interventional tasks needed to carry out guideline-compliant
screening colonoscopy, including: equipment setup, preparatory measures, sedation,
colonoscopy, adverse event management, and physician–nurse communication. Participants
can pick up equipment and place it in the correct position and freely move around
the virtual endoscopy room by walking or by “teleporting” to a different place in
the room using the handheld controllers.
A prospective multicenter study tested ViGaTu [87], including 43 nurses and 28 physicians taking part in VR training, to assess face,
content, and construct validity of this model. In total, 75 % of the items for assessing
face validity were rated as realistic and 60 % of items assessing content validity
and usefulness were rated as useful. Experienced endoscopy staff were significantly
faster than beginners in setting up the endoscope tower suggesting construct validity
(Fig. 13s; Tables 46 s, 47 s).
EndoSim simulator
The EndoSim Simulator (Surgical Science, Sweden) is designed for training in EGD,
colonoscopy, and ERCP. The complete package includes a haptic feedback hardware platform
that simulates forces during insertion and rotation of the endoscope. The system comes
with one endoscope of choice, a full-length insertion tube, a working channel, computer,
and monitor with a height-adjustable frame. The EndoSim “Cube” variant can also function
as a portable desktop unit. This simulator features an oral orifice for endoscope
insertion into a mannequin torso, after which a virtual replica of the GI tract is
generated in real time, responding dynamically to the user’s manipulation of the endoscope.
This model also provides visual, auditory, and haptic feedback to the user. The EndoSim
offers several training modules tailored to both basic and advanced endoscopic techniques.
Moreover, this model allows photodocumentation in accordance with the ESGE guidelines,
and biopsy sampling (with an assistant handling the biopsy forceps). The ERCP module
has a split-screen display, showing both endoscopic and fluoroscopic views, and allows
trainees to practice bile duct cannulation using a guidewire and sphincterotome (Table 48 s).
EndoVision Standard
The EndoVision Standard (MedVision, Tokyo, Japan) is designed for EGD, bronchoscopy,
and colonoscopy. It is equipped with two full high definition displays, including
one with a touchscreen interface that allows users to access real patient cases, virtual
tips, videos, guidelines, and visual cues. The simulator is mounted on a transportable
cart and includes a foot pedal for simulating coagulation and electric dissection.
Integrated sensor technology tracks the endoscopist’s movements upon endoscope insertion,
delivering real-time visual, auditory, and haptic feedback to simulate realistic tissue
resistance.
Biopsy, injection, balloon dilation, stenting, foreign body removal, and coagulation
can be practiced using real patient case simulations. The colonoscopy module includes
mucosal assessment in different clinical scenarios (i. e., polyps, inflammatory bowel
disease, diverticulosis, and ischemic colitis) (Table 49 s).
CLA 4/5, CLA5/4
The CLA 4/5 (Coburger Lehrmittelanstalt, CLA, Coburg, Germany) is a basic phantom
model made from plastic and is the size of an adult. This simulator is made for EGD,
colonoscopy, and bronchoscopy (Table 50s). It is equipped with a flexible mounted head, nasopharyngeal zone, upper body with
removable chest cover, and a lower body with a removable elastic abdominal cover (Fig. 14 s). There is the possibility to add many optional supplements according to the intended
procedure, and some additional pathological changes (e. g. polyps) can be added through
openings in the organs. The CLA 5/4 (Table 50s) is designed for colonoscopy and consists of lower body with a removable elastic
abdominal wall.
Prototypes
Many companies and research institutions are continuously working on cutting-edge
prototype endoscopy simulators that incorporate technologies such as haptic feedback.
The introduction of 3 D printing has allowed companies to develop prototypes for testing,
refinement, and training of new endoscopic tools more rapidly than in the past. Some
of these prototypes are currently used only in limited training programs by manufacturers
of new accessories, but others await commercial approval, for example CE marking,
to be prepared for sale and to be used on a larger scale in clinical training institutions.
What follows is a summary of the currently known prototypes for endoscopic training
(not yet commercially available) ([Table 6]).
Table 6
Prototype simulator models.
Simulator
|
Manufacturer
|
Class
|
Target
|
Interventional module
|
Material
|
Weblink
|
Hot Axios Synthetic Trainer
|
Version3 D, Netherlands with Boston Scientific
|
Mechanical
|
Hot Axios LAMS indications
|
Collection & Lumen
|
3D-printed plastic
|
https://version3 d.com/
|
Hot Axios Artificial Trainer
|
Version3 D with Boston Scientific
|
Mechanical
|
Hot Axios LAMS indications
|
Drainage of PFC/gallbladder/bile duct
|
3D-printed modules with artificial skin plates
|
https://version3 d.com/
|
CholangioBox
|
Version3 D with Boston Scientific
|
Mechanical
|
Cholangioscopy
|
Silicone ducts module
|
Silicone ducts module
|
https://version3 d.com/
|
Pentax C2 Cryoballoon Simulator
|
Lazarus 3 D, Philomath, Oregon, USA
|
Mechanical
|
EGD: Barrett’s esophagus
|
Cryoablation
|
Silicone, thermochromic pigments
|
https://www.lazarus3 d.com/skill-sure
|
EndoCubot
|
Endorobotics
|
Virtual and Mechanical
|
EGD Colonoscopy
|
Gastro module: antrum, cardia, middle body Colon module: rectum, transverse and descending colon Interventional EGD and colonoscopy (EMR, ESD, suturing)
|
Plastic and metal Phantom tissue from Kotobuki Medical
|
https://www.endorobo.com/product/endocubot.php
|
Tübingen (Biliphant) model
|
University of Tübingen
|
Mechanical
|
ERCP
|
Guidewire placement, precut sphincterotomy, stone removal, stent placement and removal
|
3 D printing and latex
|
NA
|
Frimberger Simulators
|
Prof. Frimberger
|
Mechanical
|
ERCP Colonoscopy
|
Cannulation, lithotripsy, stenting
|
NA
|
NA
|
Satoshi Model
|
Olympus Corporation, Tokyo, Japan
|
Mechanical
|
ERCP
|
Cannulation capture, sphincterotomy, guidewire insertion
|
NA
|
NA
|
Colonoscopy Training Simulator Endonix
|
Olympus Corporation
|
Virtual
|
Colonoscopy
|
Yes
|
3D-printed
|
https://www.olympusprofed.com/gi/colonoscopy/39076 /
|
EUS Magic Box
|
Dhir group
|
Mixed Mechanical/Ex vivo
|
EUS intervention
|
FNA, biliary or pancreatic duct drainage, pseudocyst drainage and gastroenterostomy
|
Pig esophagus and stomach, a silicon-based duodenum
|
NA
|
EGD, esophagogastroduodenoscopy; EMR, endoscopic mucosal resection; ERCP, endoscopic
retrograde cholangiopancreatography; ESD, endoscopic submucosa dissection; LAMS, lumen-apposing
metal stent; NA, not available.
Hot Axios Synthetic Trainer
The Synthetic 3D-printed trainer (Boston Scientific) is specifically intended for
instruction in all steps of Hot Axios placement. This trainer includes two modules:
one with a large pseudocyst to be drained, the second with a small lumen, to simulate
stent deployment in a limited space (e. g. biliary duct), in which a red light is
triggered if the opposite wall of the lumen is touched. The Synthetic training model
can be used without any investment in capital equipment (Fig. 15s; Table 51 s).
Hot Axios Artificial Trainer
This training model, from Boston Scientific, is to instruct physicians in placing
the Hot Axios in any situation where capital equipment, namely full endoscopy tower
and EUS processor, is available. The EUS-guided image provides a simulation of all
the steps in placing a Hot Axios device. Moreover, as with the abovementioned Synthetic
Trainer, this device also has two modules with different sizes of lumen for drainage.
It is a relatively simple model and not fully anatomically correct (Fig. 16s; Table 52 s).
CholangioBox
The CholangioBox, from Boston Scientific, consists of a hard plastic case with simulated
silicone biliary ducts on the inside. This model provides the endoscopist with the
ability to use all the Spyglass instruments, simulating performance in a real duct,
without the need for a duodenoscope. Stone management with electrohydraulic lithotripsy
and basket can be fully simulated, as can stricture management and acquistion of biopsies
at different sites in the silicone model (Fig. 17s; Table 53 s).
Pentax C2 Cryoballoon Simulator
This simulator (Lazarus 3 D, Philomath, Oregon, USA) permits training of cryoablation
on an artificial esophagus. The model consists of an external acrylic box with suction
feet for ease of use. Internal components include a heating element with external
controls, insulation, and an esophagus. The esophagus features realistic anatomy including
the lower esophageal sphincter and a portion of the upper stomach, and a red surface
simulating Barrett’s esophagus. Upon application of nitrous oxide to the red areas
via the cryoballoon system, the tissue changes color to dark purple/grey. This color
change is reversible, allowing multiple uses of the model. A full endoscopy tower
and gastroscope are required (Table 54 s).
EndoCubot
The Endocubot (Endorobotics Co. Ltd, Seoul, South Korea) is a VR simulator box (gastric
and colon models available) into which a standard endoscope can be inserted. Its robotic
technology-based automated position control enables simulation of various anatomical
positions that can be adjusted using the 8-inch touchscreen interface. In addition,
this model is capable of simulating insufflation and desufflation features of the
endoscope, and repetitive movements, such as respiration and heartbeats, as well as
random events such as gagging and sneezing by the patient. Phantom tissue can be inserted
to train in EMR or ESD, and electrocautery can be applied without the need for a grounding
pad. The product weighs approximately 18 kg, making it relatively cumbersome to transport
(Fig. 18s; Table 55 s).
Tübingen (Biliphant) Model
The Tübingen (Biliphant) model, developed at the University of Tübingen, is a sophisticated
training simulator designed for ERCP, particularly in cases involving altered GI anatomy
such as Billroth II or Roux-en-Y reconstructions, whose prevalence (also due to bariatric
surgery) continues to rise. This model focuses on replicating key procedural steps,
such as intubation, papilla identification, guidewire placement, and advanced interventions
such as precut sphincterotomy, stone removal, and stent placement and removal.
Studies have highlighted its effectiveness in training endoscopists to manage postoperative
anatomies. Participants in evaluation workshops reported realistic haptic feedback
and visual impressions when navigating the model’s artificial structures, with high
ratings for its suitability as a teaching tool (average scores ranging from 1.36 to
1.73 on a scale of 1 to 5 where 1, the highest score, is “very good”) [88].
This model is notable for its animal-free design, which uses advanced 3 D printing
and latex materials to recreate realistic organ textures, despite remaining limitations
such as friction between surfaces and the absence of simulated peristalsis.
Although not yet commercially available, this simulator provides a practical, anatomically
representative environment, making it a valuable tool for mastering both fundamental
and advanced ERCP maneuvers.
Frimberger Simulators
Professor Frimberger (Germany) designed a group of mechanical simulators for ERCP,
endowed with papillas in a duodenum that can be seen on the endoscopy monitor and
with a unique window, that allows visualization of what is happening beyond the papilla
in the pancreaticobiliary tract. There is a specific model for all relevant procedures
(i. e., selective cannulation of the bile ducts and plastic stenting, papillotomy
in Billroth 2 anatomy, and mechanical lithotripsy). All simulators can be equipped
with a feature called the “intraduodenal observer,” to see the duodenoscope and its
actions in the duodenal space on a second monitor. There is also a group of simulators
for diagnostic colonoscopy, aimed at developing motor and 3 D orientation skills and
for practice in straightening sigma loops, but also for therapeutic maneuvers such
as hemostasis, or for polypectomy with stalks made of electrically conductive material
and polyp heads made of silicone (Fig. 19s; Table 56 s).
Satoshi Model
This ERCP simulator (Olympus Corporation, Tokyo, Japan) is used for basic and advanced
training. The endoscopist and assistant can practice ERCP with both the prone and
supine patient position, with the same cannulation capture, sphincterotomy, and guidewire
insertion, all with Olympus ERCP products (Fig. 20 s).
Colonoscopy Training Simulator Endonix
Endonix (Olympus Corporation,Tokyo, Japan) represents a 3 D printed mock-up simulator
for training in colonoscopy for both beginners and advanced endoscopists, offering
practice in basic scope manipulation, and diagnostic and therapeutic endoscopy. It
is very easy and quick to set up, requiring only a standard laptop. It is planned
that literature on this model will be available soon (Fig. 21 s).
EUS Magic Box
Dhir et al. have reported on models for EUS training, namely on the Mumbai EUS I (Prototype)
in 2015, a stereolithography 3D-printed bile duct prototype for EUS-guided biliary
drainage [89], and on an updated version, the Mumbai EUS II in 2017 [90]. In 2022, this group designed the EUS Magic Box, consisting of an all-in-one hybrid
model consisting of a pig esophagus and stomach, a silicon-based duodenum and pancreatoicobiliary
system, a pseudocyst, and biopsy targets. This model is designed to provide simulation
of multiple interventional EUS procedures (e. g., FNA, biliary or pancreatic duct
drainage, pseudocyst drainage, and gastroenterostomy) and was graded as good or excellent
by 30 /36 trainees (83 %) [91].
Summary and Conclusions: Part 2
Animal and VR simulators offer a wide spectrum of diagnostic and therapeutic procedures,
both in endoluminal and biliary tract procedures, often within the same model. Ex
vivo simulators can provide more realistic haptic and visual feedback compared with
other classes of simulators. Moreover, their financial burden is moderate, especially
compared to VR. However, the tissue properties of explanted organs may differ from
live tissue, making some endoscopy training maneuvers more difficult, and they require
more preparation and appropriate disposal. Conversely, VR simulators do not require
special preparation, they offer multiple training scenarios with varying levels of
complexity and, above all, they provide objective measures of performance with a final
summary that can be helpful for an endoscopy training program. Nevertheless, the high
costs of VR simulators are actually the main obstacle that prevents the widespread
incorporation of these modalities into everyday clinical practice. Numerous endoscopy
simulator prototypes are currently being developed and tested, and hopefully these
will be commercially available in the near future.
To the best of our knowledge, no comprehensive comparative studies among the various
endoscopic simulators have been conducted. Therefore, the choice of a specific simulator
over another may be multifactorial, including personal preferences, available budget,
and also ethical considerations, particularly in relation to in vivo models and the
regulations set by relevant authorities.