Silicone-based simulation models for peripheral nerve microsurgery.

Abstract

There is a need for a peripheral nerve model on which surgeons-in-training can simulate the repair of nerve injuries at their own pace. Although practicing on animal models/cadavers is considered the "gold standard" of microsurgical training, the proposed model aims to provide a platform for improving the technical skills of surgical trainees prior to their practice on cadaver/animal models. In addition, this model has the potential to serve as a standardized test medium for assessing the skill sets of surgeons. Several formulations of silicone were utilized for the design and fabrication of a model which realizes the hierarchical structure of peripheral nerves. The mechanical properties were characterized via the Universal Testing Machine; the damage caused by the needle on the entry sites was assessed through scanning electron microscopy (SEM). Mechanical properties of the formulations of silicone were tested to mimic human peripheral nerves. A formulation with 83.3 wt% silicone oil and 0.1 wt% cotton fiber was chosen to be used as nerve fascicles. Both 83.3 wt% silicone oil with cotton fiber and 66.6 wt% silicone oil without fiber provided a microsuturing response similar to that of epineurium at a wall thickness of 1 mm. SEM also confirmed that the entry of the needle did not introduce significant holes at the microsuturing sites. The proposed peripheral nerve model mimicked human tissues mechanically and cosmetically, and a simulation of the repair of a fifth-degree nerve injury was achieved.