OBJECTIVETo evaluate the effects of degradation time and permeability of polymeric conduits on nerve regeneration.

METHODSAfter establishment of rat models with over 10 mm gap of sciatic nerve in right hind legs,four kinds of poly (ester, carbonate) nerve conduits was used to bridge the gaps and one group without conduit in gaps was used as control. The nerve regeneration and conduit degradation were examined both macroscopically and microscopically. The contraction of the muscle controlled by regenerated nerve was measured electrophysiologically at 4, 12 and 20 weeks after the operation.

RESULTBiodegradation time of nerve conduits in vivo was as fellows: 12 weeks in group A,4 weeks in group B and group C,and 20 weeks in group D,respectively. The histological quality of regenerative sciatic neurofibra in group A was the best among all groups (Mean rank 53.17, 38.83, 26. 60, 49.17 and 20.23,P<0.005), but the inflammatory reaction in group A was only less than that in group D and more than that in the other groups (Mean rank 45.87, 36.27, 34. 83, 51.63 and 21.4,P=0.001). The responsive rates of tibialis anterior muscle for electric stimulation in group A, B, C and D were 93.33%, 60%,20% and 73. 33%, respectively (P<0.005).

CONCLUSIONAbsorbable conduits with relatively good permeability and appropriate middle degrade time improve nerve regeneration and renovate function.