Contribution of the proximal and distal nerve stumps to peripheral nerve regeneration in silicone chambers.

The specific contribution of the proximal and distal nerve stumps across an 8 mm gap within silicone chamber regeneration models was studied. For this, proximal and distal (Group A), distal and distal (Group B) and proximal and proximal (Group C) nerve stumps were placed in opposite ends of silicone chambers. In all the groups, a tissue cable forms between the nerve stumps, demonstrating that, without distinction, proximal or distal stumps can stimulate the growth of other proximal or distal stumps. Furthermore, in Group B, the newly formed pseudo-nerve, in the absence of regenerating axons, contains a number of Schwann cells significantly similar to Group A, which confirms that proliferation and migration of Schwann cells do not require axonal presence or contact. Likewise, the findings demonstrate that, with the exception of the axons, the distal stump contributes to the peripheral nerve regeneration in the same way as the proximal stump. Finally, when proximal stumps are placed in both the opposite ends of the silicone chamber, Schwann cells and regenerating axons grow into the chamber gap from both inserts, and myelination also proceeds from both ends to the centre of the chambers.