**4.4 Bariatric surgery**

Simulation has been more widely used in laparoscopic bariatric surgery compared to other laparoscopic UGI surgery. Laparoscopic box trainers help develop basic skills, such as triangulation and spatial perception, and can be used to develop skills in laparoscopic suturing. *EndoSuture Trainer Box Simulator*, (**Figure 1**) a bariatric skills trainer has been shown to be useful in teaching and training bariatric laparoscopic surgical skills as well as being cost-effective [32].

**Figure 1.** *EndoSuture Trainer Box Simulator ([32], with permission).*

Several *ex vivo* models for training in laparoscopic bariatric surgery have been developed. A porcine jejuno-jejunostomy model was created in a box trainer [6]. Eight surgeons performed a side-to-side stapled jejuno-jejunostomy on the model before performing the surgery on a patient scheduled for a laparoscopic Roux-en-Y gastric bypass. The surgeons were assessed using a motion-tracking device. Performances were similar in surgeons forming a jejuno-jejunostomy on the cadaveric model and a real patient.

Human cadaver models are useful for developing skills in laparoscopic bariatric surgery. Thiel human cadavers (THCs) provide better emulation of real human tissue compared to an anesthetized porcine model. A recent observational study analyzing similarities between the procedures on THC and patients also showed that THC presented tissue similar to human patients [38]. Participants found that practicing on cadaver models was the best training for bariatric surgery.

There are limited studies on the use of virtual reality simulators in bariatric surgery. Giannotti et al. [21] used the LAP MentorTM (Simbionix Corporation, Cleveland, Ohio, USA) [33] simulator to assess specific skills (creation of a gastric pouch and gastrojejunal anastomosis) in bariatric surgery between a group of bariatric surgeons and non-bariatric general surgeons. These investigators found significant differences between the bariatric surgeons and the non-bariatric general surgeons. These included: median difference in volume of the pouch, percentage of fundus included in the pouch, complete dissection of angle of His, and the size and position of the enterotomies. The researchers concluded from their study that the LAP MentorTM simulator could be used as a certification tool for bariatric surgeons.

VR training on a single-port sleeve gastrectomy was used to assess novice surgeons' physical and mental workload [35]. Participants were divided into a VR group and a control group. Each group of trainees participated in their first real single-port sleeve gastrectomy (SPSG) followed a month later by their second SPSG. The VR training module was designed by VirtualiSurg Company [34] using the HTC Vive headset (HTC Corporation, New Taipei City, Taiwan). The VR environment includes a virtual theatre with use of endo-staplers and real laparoscopic instruments used in bariatric surgery with integrated sensors. The VR group underwent a VR training session in between the first and second SPSG. This study showed a decrease in mental and physical workload between the first and second surgery for the VR group compared to the control group. The limitations of the study include a small sample size (n = 10), no substitution training was proposed for the control group and the real cases were not standardized.
