A new human cadaver model for laparoscopic training using N-vinyl-2-pyrrolidone: a feasibility study

The demand for cadavers for clinical skills training is increasing. However, conventional formalin-fixed bodies are often unsuitable for surgical training because the tissues become too hard. We recently developed a new formalin-free embalming method with N-vinyl-2-pyrrolidone (pyrrolidone) that has excellent fixative, disinfectant, and preservative properties, while still keeping tissues soft and pliable. In the study reported here we investigated the feasibility of laparoscopic manipulation using pyrrolidone-fixed cadavers. Donated cadavers were embalmed either with pyrrolidone (n = 7) or with formalin-containing fixative (n = 3). A laparoscopic 12-mm trocar was inserted into the umbilical region, and CO₂ gas was insufflated. Intra-abdominal structures were observed with an endoscopic camera. In the pyrrolidone-embalmed cadavers, the abdomen remained soft and depressed. In addition, CO₂ injection resulted in a marked expansion of the abdominal cavity, and it was possible to move the laparoscope freely in all directions. Clear endoscopic images of the abdominal viscera were obtained. The gallbladder and rectum were identified by grasping the surrounding organs with forceps. By contrast, in the formalin-fixed bodies, the abdominal wall was rigid, and it was difficult to move the laparoscope in the peritoneal space and observe structures in detail. The amount of CO₂ and changes in abdominal diameter and circumference in response to CO₂ injection were significantly larger in the pyrrolidone group. In conclusion, we successfully created a sufficient pneumoperitoneum state and obtained clear endoscopic images in the pyrrolidone-embalmed cadavers. Handling and dissection of the intra-abdominal structures with forceps closely replicated real-life surgery. These findings suggest the feasibility of laparoscopic training on cadavers embalmed with this pyrrolidone fixative.