Regeneration across a partial defect in rat sciatic nerve encased in a silicone chamber.

Forty-four rat sciatic nerves with partial defects were repaired with a silicone chamber. Each partial defect was created by resecting a 10 mm segment from the tibial fascicle leaving the peroneal fascicle intact. The proximal and the distal stumps of the tibial fascicle together with the intact peroneal fascicle were encased in a single silicone chamber. After seven days a fibrin matrix had surrounded the peroneal fascicle and spanned the defect between the tibial stumps. This matrix was later invaded by non-neuronal cells and regenerating axons. Non-myelinated nerve fibres had almost regenerated across the defect by 16 days. The tetanic force of the gastrocnemius muscle 120 days after repair showed 80% recovery, which was no different from that of partial defects repaired with conventional nerve grafts. The results suggest that the silicone chamber technique could be applicable to the treatment of partially transected nerve trunks.