PERIPHERAL-NERVE REPAIR USING A POLY(ORGANO)PHOSPHAZENE TUBULAR PROSTHESIS

Nerve regeneration experiments were carried out using tubular nerve gu ides of y[(ethylalanato)(1.4)(imidazolyl)(0.6)phosphazene] (PEIP). By means of in vivo tests, this polymer was found to be biodegradable and transformed into harmless products. The tubular nerve guides were pre pared by deposition of the dissolved polymer on a glass capillary tube , followed by evaporation of the solvent (methylene dichloride). After transectioning, rat sciatic nerve stumps were immediately sutured int o the ends of 10-mm-long polymer tubes. On removal bf the prosthesis, after implantation for 45 d, a tissue cable was found bridging the ner ve stumps in all cases. Histological analysis revealed that the tissue cable was essentially composed of a regenerated nerve fibre bundle. A parallel series of experiments was undertaken to compare the use of s ilicone tubes that are not biodegradable and are most frequently used for studies of nerve regeneration with tubulization techniques, The ad vantages of biodegradable PEIP tubular nerve guides used for periphera l nerve repair are discussed.