[Chitin biological tube bridging the peripheral nerve with a small gap]

To investigate the possibility of bridging small peripheral nerve gap using a de-acetyl chitosan conduit.

The sciatic nerves of right sides were cut at SD rats. They were divided into 5 Groups randomly; Group A: epineurium suture in situ (n = 24); Group B: biological conduit with a small gap for bridging the peripheral nerve (n = 24, with 5 mm gap); Group C: epineurium suture with distal stump rotated 180 degrees (n = 24); Group D: bridging the nerve by biological conduits with a small gap, but the distal stump rotated 180 degrees (n = 24, with 5 mm gap); Group E: biological conduit with a small gap for bridging the peripheral nerve with NGF (n = 24). Electrophysiological examination, histological examination and myelinated axon counting were applied after 2, 4, 6, 8 weeks after operation respectively.

Regenerated nerve fibers were seen in the distal nerve segments of all 5 groups; The nerve conduction velocity of small gap group (group B, D) was faster than that of corresponding simple epineurium suture group (group A, C) at all 2, 4, 6, 8 week time point (P < 0.05). The myelinated axon counting of small gap group (group B, D) was faster than that of corresponding simple epineurium suture group (group A, C) at all 4, 6, 8 week time point (P < 0.01), and there was no statistically significant difference at 2 week time point.

The repair effects of chitin conduit bridging peripheral nerve with small gap (5 mm) are better than that of epineurium suture directly, and possess the potential to substitute the epineurium suture.