Laparoscopic vagotomy using mini-instruments in the rat: a new laparoscopic small animal model

Animal models are necessary for research, technical developments, and training purposes in laparoscopic surgery. Although various operations on small animals have been described, there is still a need for a simple and practical laparoscopic small animal model. We acknowledged truncal vagotomy as a simple procedure, and aimed to develop a model of laparoscopic truncal vagotomy (LTV) in the rat, an inexpensive and easily available animal.

Fifty Wistar rats were randomized into an LTV group (n = 25) and an open truncal vagotomy (OTV) group (n = 25). LTV was effected with two minitrocars inserted into the left upper and right lower quadrants. Two techniques of vagotomy were developed: first, with the esophagus in its anatomical position, and second, with the distal esophagus retracted anteriorly with a grasper inserted into the retroesophageal space. OTV was performed through a midline incision. Animals were sacrificed 24h postoperatively, and autopsy was performed.

The mean +/- SD operating time was 8.3+/-1.4 min in the LTV group and 5.5+/-0.2 min in the OTV group (P < 0.05). The laparoscopically magnified view provided a better distinction of vagal fibers compared with open surgery, with the second laparoscopic technique providing the best exposure. Complications developed in three rats (12%) from the LTV group and one (4%) from the OTV group (P > 0.05). Vagotomy was confirmed to be complete at autopsy in all of the animals.

This is the first technical description of laparoscopic peptic ulcer surgery in the rat. Although subsequent histopathological and physiological studies may be required, technically, laparoscopic vagotomy in the rat seems to be a simple, inexpensive, and expeditious small-animal model for laparoscopic research.