A Comprehensive Protocol for the Study of Sciatic Nerve Regeneration in the Rabbit
Antonio Merolli, MD FBSE; Lauren Bright, VMD PhD; Wei Chang, PhD; Joachim Kohn, PhD FBSE
Rutgers - The State University of New Jersey, Piscataway, NJ
Introduction. The majority of in-vivo studies on nerve regeneration have been done in the Rat sciatic model; it is relatively cheap, so many animals can be associated to each experimental-point for a better statistical significance. However, there are limitations with the Rat sciatic model because its small dimensions restricts the range of length and diameter of the artificial guides to be tested. The use of bigger animals, like sheep or pig or non-human primates, is significantly more expensive; so, these more translational models are used in a second experimental stage which follows the experimentation in the rat.
Materials and Methods. We defined what is needed for an effective gap-injury model to test artificial nerve-guides in the rabbit sciatic nerve. We aimed at describing a comprehensive model which may provide: 1-a reduced number of steps in production and repair of the lesion; we used a double-arm suture for a faster anchoring and accommodation of the nerve stumps inside the guide. 2-an easily reproducible technique to produce a sharp transverse cut in sectioning the nerve; 3-a standard retrieval and histological procedure where both Myelin Basic Protein (MBP) and choline acetyltransferase (ChAT) were stained together with sufficient contrast on paraffin-embedded sections (reciprocal nerve staining RNS). 3D printed tools assisted both surgery and retrieval process. All our concepts and designs were tested in 18 rabbits.
Results. We were attracted by the potential translational capability of the New Zealand White Rabbit sciatic nerve model. It allowed to use diameters and lengths which are close to the standard practice in human Hand and Wrist. Costs for the rabbit model were higher than the rat but still quite reasonable; about $150 for a Wister Rat and $300 for a New Zealand White rabbit. Operation time (from incision to suture) was around 35 (+/-8) minutes (including time for imaging documentation). Throughout the procedure the animal remained in good conditions. The recovery occurred in less than 24 hours (animal feeding, drinking and re-establishing gait). Episodes of self-biting were observed in about half of the cases but they were controlled by a mix of prevention (by collar and bandaging) and treatment by antibiotic therapy. For the histology, the nerve was sectioned at five different areas (proximal and distal stumps; proximal and distal regenerate; longitudinal central section).
Conclusions. The Rabbit sciatic model can be proposed as a new standard procedure in the study of nerve regeneration assisted by artificial devices.
Back to 2019 ePosters