Microsurgery and liver research: Lumbricus terrestris, a reliable animal model for training?

Experiments using animal models are the most common way to learn microsurgery. This expertise is necessary for liver research, microsurgical reconstruction of the esophagus by free jejunum or reconstruction of the hepatic artery during reimplantation from living donors. The goal of this prospective study is to assess the reliability of an invertebrate model for microsurgical training.

Between November 2011 and January 2012, 150 microsurgical trainings simulating vascular end-to-end microanastomoses were performed on 134 earthworms. The trainings were divided into 10 periods of 1 week each that included 15 simulations of end-to-end vascular microanastomoses: larger than 1.5mm (n=5), ranging in size from 1.0 to 1.5mm (n=5), and size less than 1.0mm (n=5). The technique is presented and documented.

For diameters greater than 1.5mm, the mean anastomosis time decreased from 17.9 ± 0.9 min to 9.9 ± 0.2 min between the first and last week of training. For training with smaller diameters, the results showed a decrease in execution time of 41.8% (diameters between 1.0 and 1.5mm) and 38.6% (diameters<1.0mm) between the first and last periods. The study underlines an improvement in the dexterity and speed of nodes' execution.

The earthworm appears to be a reliable experimental model for microsurgical training. It is more ethical than using rats, less expensive than vertebrate animal models, and allows the operator to gain in both confidence and time of execution.