Differential degeneration patterns of the proximal and distal stumps in a sciatic gap-injury model in the rabbit highlight the role of gap-length in preventing regeneration

Statement of Purpose: We wanted to study more in depths the events that take place at the level of the proximal and distal stump of a sciatic nerve gap-injury bridged by a conduit longer than 20 mm. An overview of the literature on clinical outcomes in peripheral nerve gap-injuries treated by conduits shows that they perform just as well as autografts in gaps no longer than 20mm (bearing the significant advantage of avoiding donor site morbidity). So far, a lot of research has been done in the rat sciatic nerve model, however the small length of this nerve restricts the length and diameter range of conduits to be tested. Today, the majority of conduits are clinically applied in patients suffering from injuries in the relatively small nerves of the hand and wrist; these nerves are still larger than the rat sciatic nerve. On the contrary, in the New Zealand White (NZW) rabbit sciatic nerve model the surgical field allows space for guides as long as 50 mm and with diameters that range from 2.5 mm to 3.5 mm. This makes the NZW model more translational.