**3.1 Simulation using benchtop models**

Benchtop simulators (box trainers) use laparoscopic instruments within a model. They have been mainly used to teach basic surgical skills, such as suturing and knot tying. However, more advanced trainers have been developed for more complex laparoscopic surgery, such as Nissen fundoplication, hepatectomy, and colectomy [17–19]. Benchtop models use either synthetic or animal tissues or organs. They are relatively


#### **Table 3.**

*Advantages and disadvantages of different types of simulators.*

inexpensive and give tactile feedback, however, require ongoing maintenance and materials as well as an observing trainer to give feedback for maximum effectiveness [20].

#### **3.2 Virtual and augmented reality simulators**

VR simulators allow trainees to interact with a computer-generated environment that reproduces individual skills or entire procedures. Modern VR simulators can replicate complex laparoscopic surgery, such as sleeve gastrectomies and colectomies [13, 21]. Some of the advantages of this type of simulation are that they can measure procedure metrics, such as time taken, efficiency of movements, and reliability of knots [22]. The other advantage of VR simulation is that it is convenient for the trainer as performance can be assessed remotely. One of the disadvantages of VR is the capital cost of the systems, although this is decreasing, and lack of haptic feedback.

Augmented reality combines virtual reality settings with physical materials, instruments, and feedback. In AR models, the 3D virtual model is a static preoperative snapshot of a specific part of the body. When applied in real-time, respiratory movements and the surgeon's manipulation of the organ affect the model's utility in navigated surgery [23]. It may be used as a last-minute simulation before performing complex procedures [24].

#### **3.3 Cadaver and animal models**

Cadaver and animal models have been used to simulate and teach laparoscopic procedures. This method is excellent for demonstrating tissue dissection, tissue handling, and surgical technique [20]. Animal models have the added realism of blood flow which means trainees must achieve hemostasis and vascular control. The downside of these models is that they require specialized training areas with associated logistical considerations, such as ethics approval, are very expensive, and each trainee will likely only do a part of an operation.

Animal models must be anesthetized during the procedure. Procurement, preparation, maintenance, and disposal all contribute to the expense of the project, making it difficult to apply widely. Anatomic variance and distinction between the animal model and the human equivalent may limit applicability. Porcine models, for example, cannot be utilized for right colectomies due to the anatomy of the right colon, which is not zygosed. For most left-sided colectomies and rectal procedures, porcine and canine models can be used [25].
