The surgical residents and clinical fellows learned surgical skills through apprenticeship, that is, by watching their supervisor’s operation and performing specific procedures directly in the operating room. However, owing to the complexity of recent surgery and shortage of education time [1], training in the operating room alone was insufficient to achieve skillful surgical techniques. Additionally, the surgical trainees should learn not only open but also laparoscopic or robotic surgical skills in the 21st century [2]. As the incapacity in the operating room may compromise patient safety and efficacy regarding the time use, it is important to become better-prepared surgical trainees with fundamental surgical techniques before real surgery [1]. Although learning during the actual operation would be ideal, it is unfeasible and unethical to the patients. Therefore, education programs using in vitro, in vivo, or virtual models are required to fulfill the needs of surgical trainees and achieve fundamental surgical techniques.

For intestinal anastomosis, which is a relatively simple and frequent procedure compared with other procedures, surgical residents of 3rd or 4th-year grade could perform it in the real operation under the supervision of a senior surgeon. However, in terms of pancreaticojejunostomy (PJ) anastomoses, surgical trainees rarely performed or even experienced them during the training period, particularly those in the low-volume center. As PJ is relatively rare compared with intestinal or vascular anastomosis and is related to life-threatening complications [3], the opportunity of performing the PJ by the trainees in the operating room is rare. Therefore, a training model for the PJ outside the operating room is necessary.

Several education models, such as simulation (dry-laboratory) models, or animal models, for intestinal or vascular anastomosis have already been developed [1456]. Recently, several education models for PJ anastomosis using biotissue models or animal models have been introduced and reported [7891011]. Although the animal model is more realistic than any other model, it has ethical issues and is expensive. Moreover, previous studies utilized the general objective structured assessment of technical skills (OSATS) for grading PJ performance [12], not the PJ-specific grading system, or introduced only their models and procedures. In this study, the silicone models which were similar to real intestine and pancreas were utilized, and the trainee’s surgical procedures were assessed by the PJ anastomosis-specific scoring system which was developed in our department. Therefore, this study aimed to evaluate the effectiveness of our PJ training model by observing the development of a trainee’s performance using a scoring system and to validate our scoring system.

This study protocol was approved by the Institutional Review Board in Seoul National University Hospital (No. H-2201-022-1286).

PD is one of the most complex procedures in abdominal surgery, and its complication rate is still high. In particular, postoperative pancreatic fistula (POPF), which can cause life-threatening complications, is inevitable. One study reported that the surgeon’s performance was correlated with the development of POPF [3]. For the quality of surgery and patient’ safety, sufficient practice is needed. Several studies have reported that more than 60 cases of standard PD are needed to overcome the learning curve [1516]. However, all pancreatobiliary surgical fellows cannot perform more than 60 cases in the training period, even in large-volume centers. Furthermore, it is unethical for unprepared trainees to perform the surgical procedures directly on patients [17]. Therefore, simulation-based training for repetitive practices is essential to improve surgical skills before actual practice.

There were 3 categories of education models: (1) animal, (2) simulation, and (3) virtual reality. Regarding PJ, 1 institution developed a porcine model for open and laparoscopic PJ [7]. The porcine model has an advantage in that the trainees can train their surgical techniques in live animals with similar intraabdominal organs to those of humans. This model is the most realistic. However, the cost is much more expensive than the other 2 models, the preparation before and after the training requires time and effort, and ethical issues exist. The simulation model is the most popular method as it is relatively inexpensive and requires no special space or preparation procedure. It can be divided into 2 subcategories; biotissue model and silicone model. Although the biotissue model is more delicate and realistic than the silicone model and has already been utilized in another study [9], it needs special 3-dimensional bioprinting techniques and special materials, is more expensive than the silicone model, and mass production is difficult. Virtual-reality models are appropriate for laparoscopic or robotic surgery and have become popular [18]. However, considering that these models are expensive and require special equipment, it is only possible to install them in highly selective educational institutions. We selected the silicone model as the appropriate open PJ training model considering the lowest cost and no requirement for animal and expensive equipment.

In the present study, a double-layered intestine model and pancreatic model with a 3-mm small pancreatic duct manufactured by a Korean company (SINI Inc.) were utilized (Fig. 1). The size, texture, and strength were similar to those of humans. Furthermore, the repetition of 5–10 PJ was possible with 1 intestine and pancreas model. Considering that the cost of 1 intestine and 1 pancreas model was 400 US dollars, it is efficient and economical.

Several studies revealed that the trainee’s performance improved after the simulation training of PJ anastomosis using a simulation model [811]. In this study, the total procedure time and total score of OSATS-PJ were evaluated. The total procedure times were stabilized after the 7th drill and converged to 15–20 minutes (Fig. 4). The total scores increased, and in most cases of the 7th drill and after 16 or more scores were obtained (Fig. 5). Alternatively, at least 7 practices would be minimal for performing stable PJ anastomosis. After 10 simulations, our clinical fellows could similarly perform the real open PJ anastomosis. The total procedure time was 21 minutes, and the total score was 17. Although the operation time was slightly longer in the real PJ, they performed exactly step-by-step and did not hesitate in the next step. Additionally, the trainees repeated the PJ anastomoses themselves without feedback from supervisors. Therefore, the present training system would be effective for improving PJ anastomosis skills by self-training and able to achieve the fundamental level of performing PJ anastomosis in the real surgical field. Currently, clinical fellows train their robotic PJ techniques similar to the real robotic PJ with the same PJ training model [19], and research on robotic PJ training is now in progress. We anticipate that the present PJ training model would be effective in robotic PJ training, similar to open PJ training.

In this study, the OSATS-PJ was derived from the original OSATS and focused on the modified Blumgart duct-to-mucosa PJ anastomosis. It consisted of 12 definite checklists that indicated specific procedures sequentially (Table 1). Therefore, supervisors can easily assess each procedure individually and objectively grade the entire performance. Additionally, this scoring system was modifiable so that the supervisors could revise the specific steps tailored to the surgical procedures of their institution. To investigate the reproducibility of the scoring system, 5 videos were randomly selected and duplicated. When comparing the scores between the original and duplicated videos for each supervisor, the proportion of cases with identical scores or a difference of 1 was 88.0%, 96.0%, and 100.0%, respectively (Table 2). Therefore, the proposed scoring system has objectivity and reproducibility. Furthermore, this scoring system can be applied not only to open PJ anastomosis but also to laparoscopic or robotic PJ anastomosis during real operation.

In conclusion, the present open PJ training model with silicone models was effective in improving trainees’ surgical skills. Since this model does not have ethical issues nor requires expensive equipment, it can be introduced easily and practically to the field of surgical education.