A new resorbable wrap-around implant as an alternative nerve repair technique

Poly-3-hydroxybutyrate (PHB), a bacterial storage product, is available as bioabsorbable sheets and has been used in this study for primary nerve repa ir, The aim was to assess axonal regeneration following such repair and det ermine the inflammatory response to PHB. In 20 adult cats, the transected superficial radial nerve was wrapped in PH B sheets, while primary epineural repair was carried out in the contralater al limb. At 6 and 12 months, the repair sites were assessed immunohistochem ically for macrophage infiltration and myelinated axons mere counted in the distal nerve. Mean macrophage counts across the whole width of the nerve in both groups a t 6 and 12 months showed no statistically significant difference. Nor was t here any significant difference between the two groups at both time-points in axon counts, axon diameter, myelin thickness and g-ratio. There was a st atistically significant increase in fibre diameters at 12 months, indicatin g that fibres were undergoing continuous maturation.