BIOLOGICAL PERFORMANCE OF A DEGRADABLE POLY(LACTIC ACID-EPSILON-CAPROLACTONE) NERVE GUIDE - INFLUENCE OF TUBE DIMENSIONS

One of the ways to reconstruct a nerve defect is to use a biodegradabl e nerve guide. The aim of this study was to establish a nerve guide co nstructed of an amorphous copolymer of lactic acid-caprolactone. A pil ot study was set up to elucidate the effect of the tube dimensions on nerve regeneration. Four types of nerve guides, with internal diameter s ranging from 1.12-1.23 mm and wall thicknesses ranging from 0.34-0.6 8, were tested for this purpose. We evaluated the biodegradation, fore ign body reaction and nerve regeneration by light microscopy, after th ree different implantation times (1, 2, and 3 months). After 2 months, we observed that all types of nerve guides had changed from a transpa rent to an opaque and swollen state, and that they had lost their stre ngth. The foreign body reaction was characterized by the presence of g iant cells and fibroblasts surrounding the degrading nerve guide. From this pilot study, we conclude that nerve guide type 1, with an intern al diameter of 1.23 mm and a wall thickness of 0.34 mm, can ensure ner ve regeneration in the case of a 1-cm gap in the sciatic nerve of the rat. Nerve guides types 3 and 4, with relatively small lumens, show ne rve compression due to a more pronounced swelling of the degrading tub e. (C) 1995 John Wiley & Sons, Inc.