PERIPHERAL-NERVE ELONGATION BY LASER-DOPPLER FLOWMETRY CONTROLLED EXPANSION - MORPHOLOGICAL ASPECTS

Peripheral nerve elongation by a tissue expander may offer an alternat ive to nerve grafting in the management of segmental nerve loss. We in vestigated the morphological changes in peripheral nerve following slo w nerve elongation by laser Doppler flowmetry controlled expansion in a rabbit sciatic nerve model. The animals were randomly assigned to on e of four groups, with an expander volume of 0, 5, 10 or 15 cm(3), res pectively. An elongation of up to 40% was possible with preservation o f clinical function. Nerve conduction velocity decreased in relation t o elongation. Paranodal widening, followed by remyelination of the nod e, were early and constant morphological features. Demyelination and r emyelination of whole internodes, and axonal degeneration occurred spo radically and did not correlate with elongation, rate of elongation or neurophysiological parameters, The model of laser Doppler flowmetry c ontrolled nerve expansion provides a method for remodelling of myelin sheaths and lengthening of nerve fibers without axonal damage.