[Trauma of the peripheral nervous system: experimental assessments with guided tissue regeneration]

Guided tissue regeneration open interesting perspectives in reconstructive surgery of peripheral nerves. Artificial conduits for nerve repair can be obtained with biodegradable polymers. Lactic and caproic acid copolimers and poliphosphazenes are biocompatible materials and have a slow reabsorption rate. Two types of conduits obtained with Poli[L-lactide-co-6-caprolactone] and poli [bis (etilalanate) phosphazene] were evaluAted as guides for nerve regeneration in an experimental model on two groups of six Wistar rats. Under general anesthesia and with microsurgical technique, the ischiatic nerve was bilaterally isolated. On the right side a segment of the nerve was removed to create a 10 mm gap. The defect was then repaired using the conduit. On the controlateral limb after the creation of the same defect, the nerve continuity was restored using as an autograft the segment removed from the right side. Control were performed at 30, 90, 180 days and consisted in histological and electron microscopy investigations. They showed the gradual degradation of both the conduits without signs of local toxicity. The regeneration of the nerve fibers in the lumen was not significantly different from that observed in the autologous grafts. Both the conduits may be considered effective for guided nerve regeneration, but polyphosphazenes allow the possibility of use the polymer as a carrier for neurite-promoting factors.