The development of a high-fidelity training simulator of laparoscopic surgery for choledocal cyst and biliary atresia

Satoshi Ieiri, MD, PhD, FACS, Koji Yamada, MD, Masakazu Murakami, MD, Keisuke Yano, MD, Toshio Harumatsu, MD, Tokuro Baba, MD, Shun Onishi, MD, PhD, Waka Yamada, MD, PhD, Ryuta Masuya, MD, Seiro Machigashira, MD, Kazuhiko Nakame, MD, PhD, Motoi Mukai, MD, PhD, Tatsuru Kaji, MD, PhD. Department of Pediatric Surgery, Kagoshima University

Background and Aim: Recently, laparoscopic surgery for choledocal cyst and biliary atresia has become popular in the pediatric field in light of these procedures’ approval for coverage under the national health insurance system by the government in Japan. However, the number of cases performed per institution is limited, so standardizing and improving these techniques with the accumulation of cases is difficult. Therefore, the development of a high-fidelity simulator reproducing a disease-specific surgical procedure and facilitating training using simulators is important for young pediatric surgeons. We developed a simulator of laparoscopic hepatico-jejunostomy for congenital biliary dilatation and laparoscopic portoenterostomy (Kasai’s procedure) for biliary atresia.

Materials and Methods: We developed these model through industry-university cooperation with Kyoto Kagaku Co., Ltd. A pneumoperitoneum body model of a one-year-old infant was reproduced using computed tomography (CT) data and the body surface data measured with a three-dimensional scanner (Figure 1a). The organ models inside the simulator were produced using urethane and styrene materials. Surgeons in training can change the port layout according to their preference (Figure 1b)

Results: Choledocal cyst model: This model was mainly made for laparoscopic hepatico-jejunostomy. The intestines and bile duct are organs that are grasped directly with forceps. The texture of these organs is therefore important for performing suturing operations, so the size, softness, stretch, and color were thoroughly considered. Figure 2a shows our clinical case of hepatico-jejunostomy in a one-year-old girl. We sometime use the technique of suspending the anterior wall of the hepatic duct to visualize the anastomotic site clearly and facilitate needle driving, as shown in Figure 2b. Our simulator of choledocal cyst can represent the same situation as in clinical cases. The standard diameter of the hepatic duct is 10 mm, but the diameter can be resized from a tiny 3 mm to a relatively large size. The operator can also perform duct plasty. The performance of hepatico-jejunostomy was evaluated by a leak test using liquid. Biliary atresia model: In Kasai's operation, the most important procedure is careful dissection of the remnant tissue at the hepatic portal region. In our surgical model of biliary atresia, resectable remnant tissue of the hepatic portal region was successfully reproduced, as shown in Figure 3. Detachable remnant tissue was placed on the bifurcation of the portal vein. After dissecting the remnant tissue, the operator can perform portoenterostomy. The evaluation point is homogeneous peering in points of depth and area of remnant tissue. These parameters were evaluated using an image recognition software program. The performance of portoenterostomy was evaluated by a leak test using liquid

Conclusion: We developed high-fidelity models simulating choledocal cyst and biliary atresia. A validation study using experts and trainees should be conducted in order to assess the usefulness of our models.