The use of collagen polymer tube and fibrin clot in peripheral nerve repair.

Following extensive or multiple nerve injury, repair by nerve graft is the treatment of choice. In recent years, nerve repair using tubes made of synthetic material has yielded satisfactory results in experimental animals. Previously we have demonstrated that fibrin clot formed within an impermeable silicone tube promoted nerve regeneration. In the present study, we evaluated the applicability of a nerve graft fabricated out of autologous collagen and agarose. The copolymer collagen tube, 1 cm long and filled with autologous fibrin clot was implanted between transected rat right sciatic nerve and the left sciatic nerve was similarly transected and repaired with silicone tube. After 1, 2, and 4 months the regenerated nerves were removed and processed for light microscopic and morphometric analysis. We demonstrated that both types of tubes supported extensive nerve regeneration across the gap to reach the distal segment. The collagen tubes provoked a slow foreign body response with infiltration by macrophages and foreign body giant cells which became abated after 2 months. After 4 months, the nerve regenerate was encapsulated and separated from the collagen tube by a fluid exudate. The number of myelinated axons at midpoint in the nerve regenerate in the silicone tube was 9117 +/- 282 while that in the collagen tube was 8589 +/- 137. This preliminary study has demonstrated that collagen polymer tube may have potential use in peripheral nerve repair.