HISTOLOGICAL RESPONSE TO INJECTED POLYTEF AND BIOPLASTIQUE IN THE SHEEP BRAIN

Objective To assess the histological response of the sheep brain to the intra-arterial injection of particulate plastic. Materials and methods Four sheep had either polytetrafluoroethyene-containing Polytef or silicone-containing Bioplastique injected into the left carotid artery under direct vision. Two were killed soon after and the others were studied at 6 months, The brains of the animals were examined using routine histology, phase contrast and polarized light. Results The polytetrafluoroethylene or silicone particles were identified in the two animals killed soon after the injection, and the two animals examined 6 months later. There was no evidence of demyelination and only a minimal inflammatory response to the plastic particles which had found their way into the brain parenchyma. Conclusion Demyelination does not occur in the sheep brain after intra-arterial injection of Polytef and Bioplastique, and inflammation occurs only to a minor degree.