PERIPHERAL-NERVE ELONGATION BY LASER-DOPPLER FLOWMETRY-MONITORED EXPANSION - AN EXPERIMENTAL BASIS FOR FUTURE APPLICATION IN THE MANAGEMENTOF PERIPHERAL-NERVE DEFECTS

Nerve grafting often fails to achieve optimal functional results and i s always associated with donor-site morbidity. Peripheral nerve elonga tion by the use of a tissue expander may provide a useful adjunct in t he management of segmental nerve loss. In that present study, rabbit s ciatic nerve (n = 40) was elongated by expansion while nerve blood flo w was monitored by laser Doppler flowmetry. Elongation was possible up to 40 percent with preservation of clinical nerve function. Nerve con duction velocity of the expanded nerves decreased in a linear relation to elongation. The reduction irt nerve conduction velocity may be sec ondary to the observed widening of the nodes of Ranvier and altered me mbrane properties after remyelination. Demyelination and remyelination of whole internodes and axonal degeneration occurred only sporadicall y. Thus laser Doppler flowmetry-monitored expansion provides a safe me thod for elongation of intact rabbit sciatic nerve while nerve functio n and axonal continuity are preserved. Further studies are needed befo re clinical use is considered. This technique may represent a favorabl e alternative to nerve grafting for the treatment of peripheral nerve defects.