Leckenby, Jonathan Ian; (2019) Nerve regeneration through autologous grafts: exploring the 'Bottleneck Theory' further. Doctoral thesis (Ph.D), UCL (University College London).

Preview

Text Leckenby_Thesis_Corrections.pdf - Accepted Version Download (12MB) | Preview

Abstract

Background: Two-stage free functional muscle transfer (FFMT) is the gold-standard treatment modality for unilateral congenital facial paralysis. At the first stage a cross facial nerve graft (CFNG) is harvested and coapted to an isolated buccal branch of the functioning facial nerve. The second stage involves harvesting a suitable muscle with its neurovascular pedicle and transplanting this to the face after a delay of six to nine months to permit nerve regeneration; the nerve supplying the muscle is coapted to the CFNG. Aims: The purpose of this thesis was to investigate the impact that an autologous nerve grafts has on nerve regeneration. The hypothesis being tested was that nerve grafts with a higher axonal count would yield better outcomes than those with lower axonal counts. Methods: To test this two parallel experiments were designed. Firstly, a new animal outcome measure was developed selecting the posterior auricular nerve as the subject for intervention; this is an isolated branch of the facial nerve with a distinct measureable outcome through the posterior movement of the ears and recovery of the nerve could be measured accordingly. Secondly, automated axon counts were calculated with a modified technique of serial section electron microscopy. Results: The results demonstrated that a graft with a higher axon count significantly yielded better outcomes than a graft with a lower axon count: larger grafts produced better clinical outcomes of ear movement and a higher number of axons regenerated across the graft. Discussion: It was proposed that larger grafts contained higher nerve growth factors, neurotrophins and provided better structural properties than small grafts, however larger grafts are at risk of increased central scarring through ischaemia. In conclusion, this study supports the test hypothesis that a graft with a higher axonal count will out-perform a graft with a lower axon count.

Download activity - last month

Export as JSONXMLCSV

Download activity - last 12 months

Export as CSVXMLJSON

Downloads by country - last 12 months

Export as JSONXMLCSV

Archive Staff Only

View Item