Laparoscopic liver surgery in the rat : Description of a new technique

Background: We devised a safe and simple method of liver resection with a wire loop in a small animal model. Herein the method is evaluated and combined with a tumor model for further immunological, oncological, and laparoscopic research. Methods: With the aid of a wire loop and an adapted electric generator, a liver lobe resection can be performed through three trocars (first trocar: camera; second and third trocars: instruments). This operative procedure was evaluated in 10 rats (group 1). In a second group of ACI rats, a Morris hepatoma (1 mm 3 ) was induced. After 11 days, a liver lobe resection was performed. One week after the resection an autopsy and a histological examination were performed in all animals. Results: Ten ACI rats underwent laparoscopic liver resection to evaluate the operative technique with the wire loop (group 1). All rats returned to normal feeding and activity on the 1st postoperative day. There were no deaths. At autopsy, the resection area was inconspicuous, without any sign of hematoma or bilioma. In the second group, 10 days after tumor induction, the induced hepatoma was increased (1 cm 3 ) and localized in the left liver lobe. In all rats, the liver lobe was resected without touching or laceration of the tumor. At autopsy, the resection area was inconspicuous. No tumors were found in the histological workup of liver and lungs. Conclusion: This model of laparoscopic liver resection in the rat allows a safe and simple liver lobectomy, including a total tumor resection. It should also facilitate basic ontological, immunological, and laparoscopic research.